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1. The NANOGrav 15 yr Data Set: Chromatic Gaussian Process Noise Models for Six Pulsars

Author: Bjorn Larsen, Chiara M. F. Mingarelli, Jeffrey S. Hazboun, Aurélien Chalumeau, Deborah C. Good, Joseph Simon, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Paul R. Brook, H. Thankful Cromartie, Kathryn Crowter, Megan E. DeCesar, Paul B. Demorest, Timothy Dolch, Elizabeth C. Ferrara, William Fiore, Emmanuel Fonseca, Gabriel E. Freedman, Nate Garver-Daniels, Peter A. Gentile, Joseph Glaser, Ross J. Jennings, Megan L. Jones, David L. Kaplan, Matthew Kerr, Michael T. Lam, Duncan R. Lorimer, Jing Luo, Ryan S. Lynch, Alexander McEwen, Maura A. McLaughlin, Natasha McMann, Bradley W. Meyers, Cherry Ng, David J. Nice, Timothy T. Pennucci, Benetge B. P. Perera, Nihan S. Pol, Henri A. Radovan, Scott M. Ransom, Paul S. Ray, Ann Schmiedekamp, Carl Schmiedekamp, Brent J. Shapiro-Albert, Ingrid H. Stairs, Kevin Stovall, Abhimanyu Susobhanan, Joseph K. Swiggum, Haley M. Wahl, David J. Champion, Ismaël Cognard, Lucas Guillemot, Huanchen Hu, Michael J. Keith, Kuo Liu, James W. McKee, Aditya Parthasarathy, Delphine Perrodin, Andrea Possenti, Golam M. Shaifullah, and Gilles Theureau
Subjects: Millisecond pulsars, Gravitational wave astronomy, Gravitational wave detectors, Pulsar timing method, Interstellar medium, Astronomy data analysis, Astrophysics, QB460-466
Abstract: Pulsar timing arrays (PTAs) are designed to detect low-frequency gravitational waves (GWs). GWs induce achromatic signals in PTA data, meaning that the timing delays do not depend on radio frequency. However, pulse arrival times are also affected by radio-frequency-dependent “chromatic” noise from sources such as dispersion measure (DM) and scattering delay variations. Furthermore, the characterization of GW signals may be influenced by the choice of chromatic noise model for each pulsar. To better understand this effect, we assess if and how different chromatic noise models affect the achromatic noise properties in each pulsar. The models we compare include existing DM models used by the North American Nanohertz Observatory for Gravitational waves (NANOGrav) and noise models used for the European PTA Data Release 2 (EPTA DR2). We perform this comparison using a subsample of six pulsars from the NANOGrav 15 yr data set, selecting the same six pulsars as from the EPTA DR2 six-pulsar data set. We find that the choice of chromatic noise model noticeably affects the achromatic noise properties of several pulsars. This is most dramatic for PSR J1713+0747, where the amplitude of its achromatic red noise lowers from ${\mathrm{log}}_{10}{A}_{\mathrm{RN}}=-{14.1}_{-0.1}^{+0.1}$ to $-{14.7}_{-0.5}^{+0.3}$ , and the spectral index broadens from ${\gamma }_{\mathrm{RN}}={2.6}_{-0.4}^{+0.5}$ to ${\gamma }_{\mathrm{RN}}={3.5}_{-0.9}^{+1.2}$ . We also compare each pulsar's noise properties with those inferred from the EPTA DR2, using the same models. From the discrepancies, we identify potential areas where the noise models could be improved. These results highlight the potential for custom chromatic noise models to improve PTA sensitivity to GWs.
Published: 2024
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2. The beamformer and correlator for the Large European Array for Pulsars.

Author: Roy Smits, Cees G. Bassa, Gemma H. Janssen, Ramesh Karuppusamy, Michael Kramer, Kejia Lee, Kuo Liu, James W. McKee, Delphine Perrodin, Mark B. Purver, Sotirios A. Sanidas, Benjamin W. Stappers, and Weiwei Zhu
Published: 2017
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3. Involvement of the Sardinia Radio Telescope in the Breakthrough Listen Initiatives

Author: Nicolò Antonietti, Delphine Perrodin, Emilio Molinari, Marta Burgay, Stelio Montebugnoli, Claudio Maccone, Andrea Possenti, Andrea Melis, Alessandro Navarrini, Pierpaolo Pari, Raimondo Concu, and Maura Pilia
Subjects: Radio telescope, Telescope, Engineering, Pulsar, business.industry, law, Fast radio burst, Green Bank Telescope, Astronomy, business, Search for extraterrestrial intelligence, law.invention
Abstract: The Breakthrough Listen (BL) Program is the most comprehensive search for extraterrestrial life ever done. One hundred million dollars have been invested, leading to thousands of hours of dedicated telescope time at two of the major radio astronomical facilities in the world, the Green Bank Telescope and the Parkes Telescope. In this paper, we outline how the Sardinia Radio Telescope is becoming involved in the BL initiatives. We present how we are planning to conduct observations for SETI as well as for pulsar and fast radio burst searches.
Published: 2021
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4. Common-red-signal analysis with 24-yr high-precision timing of the European Pulsar Timing Array: inferences in the stochastic gravitational-wave background search

Author: Cees Bassa, J. W. McKee, A.-S. Bak Nielsen, E. van der Wateren, J. Wang, Antoine Petiteau, Andrea Possenti, Mitchell B. Mickaliger, Alberto Sesana, Kejia Lee, Delphine Perrodin, E. Graikou, Lan Wang, A. Chalumeau, R. N. Caballero, Kang Liu, Caterina Tiburzi, N. K. Porayko, Siyuan Chen, H. Xu, Alberto Vecchio, H. Hu, M. Falxa, Gemma H. Janssen, X. J. Liu, Ramesh Karuppusamy, John Antoniadis, David Champion, Ismaël Cognard, Michael Kramer, Benetge Perera, Gregory Desvignes, Stanislav Babak, Aditya Parthasarathy, Gilles Theureau, Y J Guo, L. Speri, Lucas Guillemot, Robert D. Ferdman, S. A. Sanidas, Paulo C. C. Freire, Michael Keith, Ben Stappers, J. Jang, Jonathan R. Gair, A. Berthereau, Andrew Lyne, G. Shaifullah, A. Samajdar, R. A. Main, M. Burgay, Joris P. W. Verbiest, RUS, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE31-0015,PTA-France,Recherche d'ondes gravitationnelles avec un réseau de pulsars en France(2018), Chen, S, Caballero, R, Guo, Y, Chalumeau, A, Liu, K, Shaifullah, G, Lee, K, Babak, S, Desvignes, G, Parthasarathy, A, Hu, H, Van Der Wateren, E, Antoniadis, J, Bak Nielsen, A, Bassa, C, Berthereau, A, Burgay, M, Champion, D, Cognard, I, Falxa, M, Ferdman, R, Freire, P, Gair, J, Graikou, E, Guillemot, L, Jang, J, Janssen, G, Karuppusamy, R, Keith, M, Kramer, M, Liu, X, Lyne, A, Main, R, Mckee, J, Mickaliger, M, Perera, B, Perrodin, D, Petiteau, A, Porayko, N, Possenti, A, Samajdar, A, Sanidas, S, Sesana, A, Speri, L, Stappers, B, Theureau, G, Tiburzi, C, Vecchio, A, Verbiest, J, Wang, J, Wang, L, and Xu, H
Subjects: Spatial correlation, General relativity, Astronomy, Astrophysics, 01 natural sciences, Gravitational wave background, Pulsar, Millisecond pulsar, pulsars: general, 0103 physical sciences, gravitational wave, 010303 astronomy & astrophysics, Physics, Spectral index, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astronomy and Astrophysics, methods: data analysis, European Pulsar Timing Array, Amplitude, gravitational waves, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics - High Energy Astrophysical Phenomena, methods: data analysi, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present results from the search for a stochastic gravitational-wave background (GWB) as predicted by the theory of General Relativity using six radio millisecond pulsars from the Data Release 2 (DR2) of the European Pulsar Timing Array (EPTA) covering a timespan up to 24 years. A GWB manifests itself as a long-term low-frequency stochastic signal common to all pulsars, a common red signal (CRS), with the characteristic Hellings-Downs (HD) spatial correlation. Our analysis is performed with two independent pipelines, \eprise{} and \tn{}+\ftwo{}, which produce consistent results. A search for a CRS with simultaneous estimation of its spatial correlations yields spectral properties compatible with theoretical GWB predictions, but does not result in the required measurement of the HD correlation, as required for GWB detection. Further Bayesian model comparison between different types of CRSs, including a GWB, finds the most favoured model to be the common uncorrelated red noise described by a power-law with $A = 5.13_{-2.73}^{+4.20} \times 10^{-15}$ and $\gamma = 3.78_{-0.59}^{+0.69}$ (95\% credible regions). Fixing the spectral index to $\gamma=13/3$ as expected from the GWB by circular, inspiralling supermassive black-hole binaries results in an amplitude of $A =2.95_{-0.72}^{+0.89} \times 10^{-15}$. We implement three different models, BAYESEPHEM, LINIMOSS and EPHEMGP, to address possible Solar-system ephemeris (SSE) systematics and conclude that our results may only marginally depend on these effects. This work builds on the methods and models from the studies on the EPTA DR1. We show that under the same analysis framework the results remain consistent after the data set extension., Comment: 25 pages, 10 figures, 7 tables, 2 appendix tables and 1 appendix figure
Published: 2021
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5. General Relativity Measurements from Pulsars

Author: Delphine Perrodin, Marta Burgay, and Andrea Possenti
Subjects: Physics, Gravity (chemistry), Field (physics), 010308 nuclear & particles physics, General relativity, Astrophysics::High Energy Astrophysical Phenomena, White dwarf, Binary number, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Orbit, Neutron star, Pulsar, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics
Abstract: In this chapter, after a brief description of radio pulsars and their different manifestations, we illustrate the case of the so-called relativistic binary pulsars, which are fast-spinning neutron stars in orbit with a compact companion star, either a white dwarf or a second neutron star. Thanks to the clock-like nature of their radio signals, some of these binary pulsars can be used as test beds for General Relativity and other theories of gravity. We describe the methodology used to exploit these sources as laboratories for relativistic gravity and review some of the most important recent results in this field of research.
Published: 2020
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6. Performance analysis of the Karhunen–Loève Transform for artificial and astrophysical transmissions: denoizing and detection

Author: Delphine Perrodin, Claudio Maccone, Pierpaolo Pari, Gregory Hellbourg, Andrea Melis, Matteo Trudu, Nicolò Antonietti, Maura Pilia, Alessio Trois, ITA, and USA
Subjects: Karhunen–Loève theorem, Physics, 010308 nuclear & particles physics, Space and Planetary Science, business.industry, 0103 physical sciences, Astronomy and Astrophysics, Pattern recognition, Artificial intelligence, business, 010303 astronomy & astrophysics, 01 natural sciences
Abstract: In this work, we propose a new method of computing the Karhunen–Loève Transform (KLT) applied to complex voltage data for the detection and noise level reduction in astronomical signals. We compared this method with the standard KLT techniques based on the Toeplitz correlation matrix and we conducted a performance analysis for the detection and extraction of astrophysical and artificial signals via Monte Carlo (MC) simulations. We applied our novel method to a real data study-case: the Voyager 1 telemetry signal. We evaluated the KLT performance in an astrophysical context: our technique provides a remarkable improvement in computation time and MC simulations show significant reconstruction results for signal-to-noise ratio (SNR) down to −10 dB and comparable results with standard signal detection techniques. The application to artificial signals, such as the Voyager 1 data, shows a notable gain in SNR after the KLT.
Published: 2020

7. A pulsar-based time-scale from the International Pulsar Timing Array

Author: Sourav Chatterjee, Daniel J. Reardon, Ismaël Cognard, Gemma H. Janssen, Sarah Burke-Spolaor, Zaven Arzoumanian, Michael T. Lam, Kejia Lee, Michael Kramer, Benetge Perera, J. B. Wang, L. Guo, Renée Spiewak, Ryan Shannon, David J. Nice, Richard N. Manchester, N. D. R. Bhat, D. Matsakis, E. Graikou, Joseph Simon, Ingrid H. Stairs, R. N. Caballero, Shi Dai, Matthew Bailes, Christopher J. Russell, Alberto Sesana, Robert D. Ferdman, Lucas Guillemot, Delphine Perrodin, Xing-Jiang Zhu, Andrew Lyne, Chiara M. F. Mingarelli, C. G. Bassa, Benjamin Stappers, A. Brazier, R. van Haasteren, Timothy T. Pennucci, J. W. McKee, Yue-Fei Wang, Maura McLaughlin, Michael Keith, L. Toomey, Matthew Kerr, William A. Coles, Timothy Dolch, Stefan Oslowski, M. L. Tong, Stephen Taylor, D. J. Champion, Kang Liu, S. A. Sanidas, George Hobbs, J. K. Swiggum, Gregory Desvignes, Gilles Theureau, A. Possenti, T. J. W. Lazio, R. S. Lynch, G. Shaifullah, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Hobbs, G, Guo, L, Caballero, R, Coles, W, Lee, K, Manchester, R, Reardon, D, Matsakis, D, Tong, M, Arzoumanian, Z, Bailes, M, Bassa, C, Bhat, N, Brazier, A, Burke-Spolaor, S, Champion, D, Chatterjee, S, Cognard, I, Dai, S, Desvignes, G, Dolch, T, Ferdman, R, Graikou, E, Guillemot, L, Janssen, G, Keith, M, Kerr, M, Kramer, M, Lam, M, Liu, K, Lyne, A, Lazio, T, Lynch, R, Mckee, J, Mclaughlin, M, Mingarelli, C, Nice, D, Osłowski, S, Pennucci, T, Perera, B, Perrodin, D, Possenti, A, Russell, C, Sanidas, S, Sesana, A, Shaifullah, G, Shannon, R, Simon, J, Spiewak, R, Stairs, I, Stappers, B, Swiggum, J, Taylor, S, Theureau, G, Toomey, L, van Haasteren, R, Wang, J, Wang, Y, Zhu, X, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), ITA, USA, GBR, FRA, DEU, AUS, CAN, NLD, CHN, and HUN
Subjects: Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Stability (probability), general [pulsars], Pulsar, Millisecond pulsar, Observatory, pulsars: general, 0103 physical sciences, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, time, Physics, 010308 nuclear & particles physics, Gravitational wave, Spectral density, Astronomy and Astrophysics, Atomic clock, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics - Instrumentation and Methods for Astrophysics, Noise (radio), Astronomical and Space Sciences
Abstract: We have constructed a new timescale, TT(IPTA16), based on observations of radio pulsars presented in the first data release from the International Pulsar Timing Array (IPTA). We used two analysis techniques with independent estimates of the noise models for the pulsar observations and different algorithms for obtaining the pulsar timescale. The two analyses agree within the estimated uncertainties and both agree with TT(BIPM17), a post-corrected timescale produced by the Bureau International des Poids et Mesures (BIPM). We show that both methods could detect significant errors in TT(BIPM17) if they were present. We estimate the stability of the atomic clocks from which TT(BIPM17) is derived using observations of four rubidium fountain clocks at the US Naval Observatory. Comparing the power spectrum of TT(IPTA16) with that of these fountain clocks suggests that pulsar-based timescales are unlikely to contribute to the stability of the best timescales over the next decade, but they will remain a valuable independent check on atomic timescales. We also find that the stability of the pulsar-based timescale is likely to be limited by our knowledge of solar-system dynamics, and that errors in TT(BIPM17) will not be a limiting factor for the primary goal of the IPTA, which is to search for the signatures of nano-Hertz gravitational waves., Comment: accepted by MNRAS
Published: 2020
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8. The Lowest-frequency Fast Radio Bursts: Sardinia Radio Telescope Detection of the Periodic FRB 180916 at 328 MHz

Author: Alessandro Ridolfi, Keith C. Gendreau, C. Pittori, V. Savchenko, Gianni Bernardi, Piergiorgio Casella, Massimo Turatto, G. A. Rodriguez Castillo, Giovanni Naldi, Luciano Nicastro, Marco Tavani, M. Burgay, Alessandro Papitto, M. Trudu, A. Burtovoi, Andrea Possenti, Alessandro Corongiu, Vishal Gajjar, Eliana Palazzi, Filippo Ambrosino, Maura Pilia, Alessio Trois, Giuseppe Pupillo, Adriano Ghedina, P. Ochner, Luca Zampieri, C. Casentini, Delphine Perrodin, F. Verrecchia, Massimo Cecconi, Germano Bianchi, Carlo Ferrigno, Giancarlo Setti, Nanda Rea, Francesca Panessa, Giampiero Naletto, A. Ursi, Michele Fiori, European Commission, European Research Council, Generalitat de Catalunya, Agencia Estatal de Investigación (España), and Ministerio de Ciencia, Innovación y Universidades (España)
Subjects: 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 7. Clean energy, 01 natural sciences, Optical telescope, Luminosity, law.invention, Radio telescope, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, High Energy Astrophysical Phenomena (astro-ph.HE), Repeater, Physics, Millisecond, Fast radio burst, Astronomy and Astrophysics, Photometer, Supernova, Space and Planetary Science, Physics::Accelerator Physics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: arXiv:2003.12748v2, et al., We report on the lowest-frequency detection to date of three bursts from the fast radio burst FRB 180916.J0158+65, observed at 328 MHz with the Sardinia Radio Telescope (SRT). The SRT observed the periodic repeater FRB 180916.J0158+65 for five days from 2020 February 20 to 24 during a time interval of active radio bursting, and detected the three bursts during the first hour of observations; no more bursts were detected during the remaining ~30 hr. Simultaneous SRT observations at 1548 MHz did not detect any bursts. Burst fluences are in the range 37 to 13 Jy ms. No relevant scattering is observed for these bursts. We also present the results of the multi-wavelength campaign we performed on FRB 180916.J0158+65, during the five days of the active window. Simultaneously with the SRT observations, others with different time spans were performed with the Northern Cross at 408 MHz, with XMM-Newton, NICER, INTEGRAL, AGILE, and with the TNG and two optical telescopes in Asiago, which are equipped with fast photometers. XMM-Newton obtained data simultaneously with the three bursts detected by the SRT, and determined a luminosity upper limit in the 0.3–10 keV energy range of ~1045 erg s−1 for the burst emission. AGILE obtained data simultaneously with the first burst and determined a fluence upper limit in the MeV range for millisecond timescales of ${10}^{-8}\,\mathrm{erg}\,{\mathrm{cm}}^{-2}$. Our results show that absorption from the circumburst medium does not significantly affect the emission from FRB 180916.J0158+65, thus limiting the possible presence of a superluminous supernova around the source, and indicate that a cutoff for the bursting mechanism, if present, must be at lower frequencies. Our multi-wavelength campaign sensitively constrains the broadband emission from FRB 180916.J0158+65, and provides the best limits so far for the electromagnetic response to the radio bursting of this remarkable source of fast radio bursts., A.Po., M.B. and A.R. gratefully acknowledge financial support from the research grant “iPeska” (P.I. Andrea Possenti) funded under the INAF national call PRIN-SKA/CTA with Presidential Decree 70/2016. V.G. is supported by Breakthrough Listen, which is managed by the Breakthrough Initiatives and sponsored by the Breakthrough Prize Foundation (http://www.breakthroughinitiatives.org). F.P. acknowledges financial support from ASI/INAF agreement n.2019-35-HH.0 and PRIN-INAF SKA-CTA 2016. A.Pa. and L.Z. acknowledge financial support from the Italian Space Agency (ASI) and National Institute for Astrophysics (INAF) under agreements ASI-INAF I/037/12/0 and ASI-INAF n.2017-14-H.0 and from INAF Sostegno alla ricerca scientifica main streams dellINAF, Presidential Decree 43/2018. N.R. is supported by the ERC Consolidator Grant “MAGNESIA” under grant agreement Nr. 817661, Catalan grant SGR2017-1383, Spanish grant PGC2018-095512-BI00, and acknowledge support from the PHAROS COST Action (CA16214). The Sardinia Radio Telescope is funded by the Department of Universities and Research (MIUR), the Italian Space Agency (ASI), and the Autonomous Region of Sardinia (RAS), and is operated as a National Facility by the National Institute for Astrophysics (INAF).
Published: 2020

9. Measuring Interstellar Delays of PSR J0613-0200 over 7 years, using the Large European Array for Pulsars

Author: M. Gaikwad, Kejia Lee, S. Sanidas, C. G. Bassa, Siyuan Chen, John Antoniadis, Mitchell B. Mickaliger, Gemma H. Janssen, Weiwei Zhu, Benjamin Stappers, Long Wang, H. Hu, G. Mall, Delphine Perrodin, Olaf Wucknitz, Michael Kramer, Caterina Tiburzi, Ramesh Karuppusamy, Ismaël Cognard, R. A. Main, J. W. McKee, Kang Liu, Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), ITA, GBR, FRA, DEU, CAN, GRC, NLD, and CHN
Subjects: Astronomy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, 01 natural sciences, law.invention, Telescope, pulsars: individual: PSR J0613−0200, Pulsar, Millisecond pulsar, law, pulsars: general, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Scintillation, 010308 nuclear & particles physics, Scattering, Gravitational wave, Spectral density, Astronomy and Astrophysics, Pulse (physics), Space and Planetary Science, [SDU]Sciences of the Universe [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - High Energy Astrophysical Phenomena
Abstract: Using data from the Large European Array for Pulsars (LEAP), and the Effelsberg telescope, we study the scintillation parameters of the millisecond pulsar J0613-0200 over a 7 year timespan. The "secondary spectrum" -- the 2D power spectrum of scintillation -- presents the scattered power as a function of time delay, and contains the relative velocities of the pulsar, observer, and scattering material. We detect a persistent parabolic scintillation arc, suggesting scattering is dominated by a thin, anisotropic region. The scattering is poorly described by a simple exponential tail, with excess power at high delays; we measure significant, detectable scattered power at times out to $\sim 5 \mu s$, and measure the bulk scattering delay to be between 50 to 200\,ns with particularly strong scattering throughout 2013. These delays are too small to detect a change of the pulse profile shape, yet they would change the times-of-arrival as measured through pulsar timing. The arc curvature varies annually, and is well fit by a one-dimensional scattering screen $\sim 40\%$ of the way towards the pulsar, with a changing orientation during the increased scattering in 2013. Effects of uncorrected scattering will introduce time delays correlated over time in individual pulsars, and may need to be considered in gravitational wave analyses. Pulsar timing programs would benefit from simultaneously recording in a way that scintillation can be resolved, in order to monitor the variable time delays caused by multipath propagation., Comment: 12 pages, 10 figures. Published in MNRAS
Published: 2020
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10. Investigating the high-frequency spectral features of SNRs Tycho, W44, and IC443 with the Sardinia Radio Telescope

Author: M. N. Iacolina, Delphine Perrodin, S. Loru, G. Serra, Raimondo Concu, M. Marongiu, G. Murtas, E. Egron, A. Ingallinera, A. Pellizzoni, Oleh Petruk, Maura Pilia, Alessio Trois, M. Cardillo, Francesco Gaudiomonte, Simona Righini, Matteo Bachetti, S. Mulas, Franco Buffa, Alessandro Navarrini, Roberto Ricci, G. Valente, Andrea Melis, and ITA
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Spectral line, Radio telescope, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Spinning dust, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, High Energy Physics - Phenomenology, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Spectral energy distribution, Radio frequency, Astrophysics - High Energy Astrophysical Phenomena, Noise (radio), Radio wave, Fermi Gamma-ray Space Telescope
Abstract: The main characteristics in the radio continuum spectra of Supernova Remnants (SNRs) result from simple synchrotron emission. In addition, electron acceleration mechanisms can shape the spectra in specific ways, especially at high radio frequencies. These features are connected to the age and the peculiar conditions of the local interstellar medium interacting with the SNR. Whereas the bulk radio emission is expected at up to $20-50$ GHz, sensitive high-resolution images of SNRs above 10 GHz are lacking and are not easily achievable, especially in the confused regions of the Galactic Plane. In the framework of the early science observations with the Sardinia Radio Telescope in February-March 2016, we obtained high-resolution images of SNRs Tycho, W44 and IC443 that provided accurate integrated flux density measurements at 21.4 GHz: 8.8 $\pm$ 0.9 Jy for Tycho, 25 $\pm$ 3 Jy for W44 and 66 $\pm$ 7 Jy for IC443. We coupled the SRT measurements with radio data available in the literature in order to characterise the integrated and spatially-resolved spectra of these SNRs, and to find significant frequency- and region-dependent spectral slope variations. For the first time, we provide direct evidence of a spectral break in the radio spectral energy distribution of W44 at an exponential cutoff frequency of 15 $\pm$ 2 GHz. This result constrains the maximum energy of the accelerated electrons in the range $6-13$ GeV, in agreement with predictions indirectly derived from AGILE and \textit{Fermi}-LAT gamma-ray observations. With regard to IC443, our results confirm the noticeable presence of a bump in the integrated spectrum around $20-70$ GHz that could result from a spinning dust emission mechanism., 12 pages, 9 figures
Published: 2018
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11. The International Pulsar Timing Array: Second data release

Author: Sarah Burke-Spolaor, Robert D. Ferdman, Stephen Taylor, Lei Zhang, Janna Goldstein, Caterina Tiburzi, Alberto Sesana, Ingrid H. Stairs, Elizabeth C. Ferrara, N. D. R. Bhat, Benetge Perera, Aditya Parthasarathy, Michael Kramer, H. Hu, Richard N. Manchester, Joseph Simon, L. Lentati, Matthew Kerr, Shi Dai, R. N. Caballero, Megan E. DeCesar, Paul Demorest, A. Possenti, Xing-Jiang Zhu, Kathryn Crowter, Weiwei Zhu, C. G. Bassa, Emmanuel Fonseca, Kejia Lee, Scott M. Ransom, Michael Keith, Stefan Oslowski, Chiara M. F. Mingarelli, D. J. Champion, Ramesh Karuppusamy, David J. Nice, Andrew Lyne, Timothy T. Pennucci, Timothy Dolch, J. K. Swiggum, Benjamin Stappers, K. Islo, Lucas Guillemot, Michele Vallisneri, J. B. Wang, X. Siemens, Gregory Desvignes, Gilles Theureau, James M. Cordes, Ismaël Cognard, Renée Spiewak, Siyuan Chen, Jing Luo, S. A. Sanidas, P. T. Baker, A. Brazier, Songbo Zhang, Alberto Vecchio, George Hobbs, Delphine Perrodin, Michael T. Lam, Jeffrey S. Hazboun, M. Burgay, Daniel J. Reardon, Zaven Arzoumanian, G. Shaifullah, J. W. McKee, Maura McLaughlin, Christopher J. Russell, Sourav Chatterjee, Kang Liu, Matthew Bailes, Gemma H. Janssen, Ryan Shannon, E. Graikou, Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Perera, B, Decesar, M, Demorest, P, Kerr, M, Lentati, L, Nice, D, Osłowski, S, Ransom, S, Keith, M, Arzoumanian, Z, Bailes, M, Baker, P, Bassa, C, Bhat, N, Brazier, A, Burgay, M, Burke-Spolaor, S, Caballero, R, Champion, D, Chatterjee, S, Chen, S, Cognard, I, Cordes, J, Crowter, K, Dai, S, Desvignes, G, Dolch, T, Ferdman, R, Ferrara, E, Fonseca, E, Goldstein, J, Graikou, E, Guillemot, L, Hazboun, J, Hobbs, G, Hu, H, Islo, K, Janssen, G, Karuppusamy, R, Kramer, M, Lam, M, Lee, K, Liu, K, Luo, J, Lyne, A, Manchester, R, Mckee, J, Mclaughlin, M, Mingarelli, C, Parthasarathy, A, Pennucci, T, Perrodin, D, Possenti, A, Reardon, D, Russell, C, Sanidas, S, Sesana, A, Shaifullah, G, Shannon, R, Siemens, X, Simon, J, Spiewak, R, Stairs, I, Stappers, B, Swiggum, J, Taylor, S, Theureau, G, Tiburzi, C, Vallisneri, M, Vecchio, A, Wang, J, Zhang, S, Zhang, L, Zhu, W, Zhu, X, Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Technologie de Belfort-Montbeliard (UTBM), PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Ephemeris, 01 natural sciences, Pulsar timing array, stars: neutron, neutron [stars], Pulsar, Millisecond pulsar, Observatory, pulsars: general, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, methods: data analysis, European Pulsar Timing Array, gravitational waves, Space and Planetary Science, [SDU]Sciences of the Universe [physics], pulsars, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Noise (radio), Methods: data analysi
Abstract: In this paper, we describe the International Pulsar Timing Array second data release, which includes recent pulsar timing data obtained by three regional consortia: the European Pulsar Timing Array, the North American Nanohertz Observatory for Gravitational Waves, and the Parkes Pulsar Timing Array. We analyse and where possible combine high-precision timing data for 65 millisecond pulsars which are regularly observed by these groups. A basic noise analysis, including the processes which are both correlated and uncorrelated in time, provides noise models and timing ephemerides for the pulsars. We find that the timing precisions of pulsars are generally improved compared to the previous data release, mainly due to the addition of new data in the combination. The main purpose of this work is to create the most up-to-date IPTA data release. These data are publicly available for searches for low-frequency gravitational waves and other pulsar science., Comment: Submitted to MNRAS and in review, 23 pages, 5 figures
Published: 2019
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12. Tests of gravitational symmetries with pulsar binary J1713+0747

Author: Michael Kramer, Kang Liu, Robert D. Ferdman, Lina Levin, P. Lazarus, Marjorie Gonzalez, Michael T. Lam, Gemma H. Janssen, Kejia Lee, Timothy Dolch, Norbert Wex, Scott M. Ransom, Kathryn Crowter, A. Jessner, Ramesh Karuppusamy, J. K. Swiggum, Andrew Lyne, K. Lazaridis, M. L. Jones, Gregory Desvignes, J. W. McKee, Gilles Theureau, Ismaël Cognard, R. Smits, Maura McLaughlin, A. Krieger, Weiwei Zhu, M. Burgay, D. J. Champion, Timothy T. Pennucci, Delphine Perrodin, Caterina Tiburzi, L. Lentati, Kevin Stovall, Joris P. W. Verbiest, A. Possenti, Christine Jordan, Glenn Jones, G. Shaifullah, E. Graikou, J. A. Ellis, David J. Nice, R. N. Caballero, Ingrid H. Stairs, Stefan Oslowski, Jason W. T. Hessels, C. G. Bassa, Emmanuel Fonseca, Benjamin Stappers, S. A. Sanidas, Zaven Arzoumanian, Lucas Guillemot, Paul Demorest, High Energy Astrophys. & Astropart. Phys (API, FNWI), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Centre National de la Recherche Scientifique ( CNRS ) -Université d'Orléans ( UO ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Unité Scientifique de la Station de Nançay ( USN ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Univers et Théories ( LUTH ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Zhu, W, Desvignes, G, Wex, N, Caballero, R, Champion, D, Demorest, P, Ellis, J, Janssen, G, Kramer, M, Krieger, A, Lentati, L, Nice, D, Ransom, S, Stairs, I, Stappers, B, Verbiest, J, Arzoumanian, Z, Bassa, C, Burgay, M, Cognard, I, Crowter, K, Dolch, T, Ferdman, R, Fonseca, E, Gonzalez, M, Graikou, E, Guillemot, L, Hessels, J, Jessner, A, Jones, G, Jones, M, Jordan, C, Karuppusamy, R, Lam, M, Lazaridis, K, Lazarus, P, Lee, K, Levin, L, Liu, K, Lyne, A, Mckee, J, Mclaughlin, M, Osłowski, S, Pennucci, T, Perrodin, D, Possenti, A, Sanidas, S, Shaifullah, G, Smits, R, Stovall, K, Swiggum, J, Theureau, G, Tiburzi, C, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: General relativity, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astronomy, FOS: Physical sciences, Astrophysics, Lorentz covariance, 01 natural sciences, Binary pulsar, Gravitation, stars: neutron, General Relativity and Quantum Cosmology, Pulsar, Gravitational field, 0103 physical sciences, pulsars: individual (PSR J1713+0747), 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astronomy and Astrophysics, Gravitational constant, European Pulsar Timing Array, binaries: general, Space and Planetary Science, [SDU]Sciences of the Universe [physics], gravitation, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: Symmetries play an important role in modern theories of gravity. The strong equivalence principle (SEP) constitutes a collection of gravitational symmetries which are all implemented by general relativity. Alternative theories, however, are generally expected to violate some aspects of SEP. We test three aspects of SEP using observed change rates in the orbital period and eccentricity of binary pulsar J1713+0747: 1. the gravitational constant's constancy as part of locational invariance of gravitation; 2. the post-Newtonian parameter $\hat{\alpha}_3$ in gravitational Lorentz invariance; 3. the universality of free fall (UFF) for strongly self-gravitating bodies. Based on the pulsar timing result of the combined dataset from the North American Nanohertz Gravitational Observatory (NANOGrav) and the European Pulsar Timing Array (EPTA), we find $\dot{G}/G = (-0.1 \pm 0.9) \times 10^{-12}\,{\rm yr}^{-1}$, which is weaker than Solar system limits, but applies for strongly self-gravitating objects. Furthermore, we obtain the constraints $|\Delta|< 0.002$ for the UFF test and $-3\times10^{-20} < \hat{\alpha}_3 < 4\times10^{-20}$ at 95% confidence. These are the first direct UFF and $\hat{\alpha}_3$ tests based on pulsar binaries, and they overcome various limitations of previous tests., Comment: 11 pages, 6 figures, and 1 table; submitted to MNRAS
Published: 2019
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13. A detailed study of giant pulses from PSR B1937+21 using the Large European Array for Pulsars

Author: Si Chen, Michael Kramer, J. W. McKee, Delphine Perrodin, Benjamin Stappers, M. Gaikwad, Gemma H. Janssen, Weiwei Zhu, C. G. Bassa, Kejia Lee, Long Wang, Kang Liu, S. A. Sanidas, Ramesh Karuppusamy, Ismaël Cognard, R. Smits, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), ITA, GBR, FRA, DEU, NLD, and CHN
Subjects: FOS: Physical sciences, Astrophysics, 01 natural sciences, Power law, stars: neutron, Time of arrival, Pulsar, Millisecond pulsar, stars: rotation, pulsars: general, 0103 physical sciences, structure, 010303 astronomy & astrophysics, pulsar, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, polarization, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, business.industry, Astronomy and Astrophysics, radiation mechanisms: non-thermal, Polarization (waves), Fractional polarization, Interstellar medium, modulation, pulsars: individual (PSR J1939+2134), Space and Planetary Science, [SDU]Sciences of the Universe [physics], correlation, fractional, Global Positioning System, pulsars: individual (PSR B1937+21), Astrophysics - High Energy Astrophysical Phenomena, business, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: We have studied 4265 giant pulses (GPs) from the millisecond pulsar B1937+21; the largest-ever sample gathered for this pulsar, in observations made with the Large European Array for Pulsars. The pulse energy distribution of GPs associated with the interpulse are well-described by a power law, with index $\alpha = -3.99 \pm 0.04$, while those associated with the main pulse are best-described by a broken power law, with the break occurring at $\sim7$ Jy $\mu$s, with power law indices $\alpha_{\text{low}} = -3.48 \pm 0.04$ and $\alpha_{\text{high}} = -2.10 \pm 0.09$. The modulation indices of the GP emission are measured, which are found to vary by $\sim0.5$ at pulse phases close to the centre of the GP phase distributions. We find the frequency-resolved structure of GPs to vary significantly, and in a manner that cannot be attributed to the interstellar medium influence on the observed pulses. We examine the distribution of polarisation fractions of the GPs and find no correlation between GP emission phase and fractional polarisation. We use the GPs to time PSR B1937+21 and although the achievable time of arrival precision of the GPs is approximately a factor of two greater than that of the average pulse profile, there is a negligible difference in the precision of the overall timing solution when using the GPs., Comment: 20 pages, 21 figures, 3 tables, accepted for publication in MNRAS
Published: 2019
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14. High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array

Author: P. Lazarus, R. van Haasteren, Christine Jordan, Pablo Rosado, Jason W. T. Hessels, S. Babak, Alberto Sesana, Joris P. W. Verbiest, Chiara M. F. Mingarelli, Benjamin Stappers, A. Jessner, D. J. Champion, J. W. McKee, J. R. Gair, Lucas Guillemot, Delphine Perrodin, Antoine Petiteau, P. Brem, Michael Kramer, Ramesh Karuppusamy, Andrew Lyne, Ismaël Cognard, Gregory Desvignes, Gilles Theureau, Kejia Lee, G. Shaifullah, E. Graikou, M. Burgay, Stefan Oslowski, M. B. Purver, Caterina Tiburzi, R. Smits, K. Lazaridis, Stephen Taylor, R. N. Caballero, Kang Liu, C. G. Bassa, A. Lassus, Gemma H. Janssen, Alberto Vecchio, S. Sanidas, L. Lentati, A. Possenti, Desvignes, G, Caballero, R, Lentati, L, Verbiest, J, Champion, D, Stappers, B, Janssen, G, Lazarus, P, Osłowski, S, Babak, S, Bassa, C, Brem, P, Burgay, M, Cognard, I, Gair, J, Graikou, E, Guillemot, L, Hessels, J, Jessner, A, Jordan, C, Karuppusamy, R, Kramer, M, Lassus, A, Lazaridis, K, Lee, K, Liu, K, Lyne, A, Mckee, J, Mingarelli, C, Perrodin, D, Petiteau, A, Possenti, A, Purver, M, Rosado, P, Sanidas, S, Sesana, A, Shaifullah, G, Smits, R, Taylor, S, Theureau, G, Tiburzi, C, van Haasteren, R, Vecchio, A, Max-Planck-Institut für Radioastronomie (MPIFR), Cavendish Laboratory, University of Cambridge [UK] (CAM), Universität Bielefeld, Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Netherlands Institute for Radio Astronomy ( ASTRON ), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), University of Amsterdam [Amsterdam] (UvA), Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], APC - Gravitation (APC-Gravitation), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Centre for Astrophysics and Supercomputing [Swinburne] (CAS), Swinburne University of Technology [Melbourne], Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Theoretical Astrophysics [Pasadena] (TAPIR), California Institute of Technology (CALTECH), Birmingham City University (BCU), National Natural Science Foundation of China (Grant No.11373011)., European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Division of Physics, Mathematics and Astronomy [Pasadena], California Institute of Technology (CALTECH)-California Institute of Technology (CALTECH), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: astro-ph.SR, FOS: Physical sciences, Proper motion, Astrophysics, Magnetar, 01 natural sciences, Radio spectrum, Radio telescope, Pulsar timing array, proper motions, Pulsar, Millisecond pulsar, 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Stars: Distance, astro-ph.HE, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, Pulsars: General, Astronomy, Astronomy and Astrophysics, pulsars:general, European Pulsar Timing Array, Neutron star, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, stars: distances, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, stars:distances, astro-ph.IM
Abstract: We report on the high-precision timing of 42 radio millisecond pulsars (MSPs) observed by the European Pulsar Timing Array (EPTA). This EPTA Data Release 1.0 extends up to mid-2014 and baselines range from 7-18 years. It forms the basis for the stochastic gravitational-wave background, anisotropic background, and continuous-wave limits recently presented by the EPTA elsewhere. The Bayesian timing analysis performed with TempoNest yields the detection of several new parameters: seven parallaxes, nine proper motions and, in the case of six binary pulsars, an apparent change of the semi-major axis. We find the NE2001 Galactic electron density model to be a better match to our parallax distances (after correction from the Lutz-Kelker bias) than the M2 and M3 models by Schnitzeler (2012). However, we measure an average uncertainty of 80\% (fractional) for NE2001, three times larger than what is typically assumed in the literature. We revisit the transverse velocity distribution for a set of 19 isolated and 57 binary MSPs and find no statistical difference between these two populations. We detect Shapiro delay in the timing residuals of PSRs J1600$-$3053 and J1918$-$0642, implying pulsar and companion masses $m_p=1.22_{-0.35}^{+0.5} \text{M}_{\odot}$, $m_c = 0.21_{-0.04}^{+0.06} \text{M}_{\odot }$ and $m_p=1.25_{-0.4}^{+0.6} \text{M}_{\odot}$, $m_c = 0.23_{-0.05}^{+0.07} \text{M}_{\odot }$, respectively. Finally, we use the measurement of the orbital period derivative to set a stringent constraint on the distance to PSRs J1012$+$5307 and J1909$-$3744, and set limits on the longitude of ascending node through the search of the annual-orbital parallax for PSRs J1600$-$3053 and J1909$-$3744., Comment: 42 pages, 11 figures. Accepted for publication in MNRAS
Published: 2016
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15. From spin noise to systematics: stochastic processes in the first International Pulsar Timing Array data release

Author: R. van Haasteren, Scott M. Ransom, S. Babak, Antoine Petiteau, Paul Demorest, L. Toomey, Gemma H. Janssen, Alberto Sesana, Marjorie Gonzalez, Sourav Chatterjee, A. Lassus, Ryan Shannon, Justin A. Ellis, Glenn Jones, E. Graikou, J. W. McKee, Kang Liu, Kejia Lee, Matthew Kerr, Sarah Burke-Spolaor, William A. Coles, Maura McLaughlin, G. Shaifullah, Stephen Taylor, Weiwei Zhu, P. Lazarus, S. A. Sanidas, D. J. Champion, Delphine Perrodin, R. N. Caballero, Kevin Stovall, Joris P. W. Verbiest, Benetge Perera, Richard N. Manchester, C. G. Bassa, Emmanuel Fonseca, Jonathan R. Gair, George Hobbs, D. R. Madison, R. Smits, Alberto Vecchio, Daniel R. Stinebring, Michael T. Lam, Daniel J. Reardon, X. P. You, Zaven Arzoumanian, Paul D. Lasky, Yue-Fei Wang, Lucas Guillemot, R. S. Lynch, Pablo Rosado, Lina Levin, Xing-Jiang Zhu, Chiara M. F. Mingarelli, L. Lentati, Benjamin Stappers, A. Possenti, T. J. W. Lazio, Robert D. Ferdman, Stefan Oslowski, J. K. Swiggum, X. Siemens, Gregory Desvignes, Gilles Theureau, Ramesh Karuppusamy, Ismaël Cognard, M. Burgay, Timothy T. Pennucci, Michele Vallisneri, J. B. Wang, James M. Cordes, Sean T. McWilliams, David J. Nice, P. Brem, W. van Straten, Caterina Tiburzi, N. D. R. Bhat, Shi Dai, Jason W. T. Hessels, Ingrid H. Stairs, Timothy Dolch, Michael Kramer, Michael Keith, Lentati, L, Shannon, R, Coles, W, Verbiest, J, van Haasteren, R, Ellis, J, Caballero, R, Manchester, R, Arzoumanian, Z, Babak, S, Bassa, C, Bhat, N, Brem, P, Burgay, M, Burke-Spolaor, S, Champion, D, Chatterjee, S, Cognard, I, Cordes, J, Dai, S, Demorest, P, Desvignes, G, Dolch, T, Ferdman, R, Fonseca, E, Gair, J, Gonzalez, M, Graikou, E, Guillemot, L, Hessels, J, Hobbs, G, Janssen, G, Jones, G, Karuppusamy, R, Keith, M, Kerr, M, Kramer, M, Lam, M, Lasky, P, Lassus, A, Lazarus, P, Lazio, T, Lee, K, Levin, L, Liu, K, Lynch, R, Madison, D, Mckee, J, Mclaughlin, M, Mcwilliams, S, Mingarelli, C, Nice, D, Osłowski, S, Pennucci, T, Perera, B, Perrodin, D, Petiteau, A, Possenti, A, Ransom, S, Reardon, D, Rosado, P, Sanidas, S, Sesana, A, Shaifullah, G, Siemens, X, Smits, R, Stairs, I, Stappers, B, Stinebring, D, Stovall, K, Swiggum, J, Taylor, S, Theureau, G, Tiburzi, C, Toomey, L, Vallisneri, M, van Straten, W, Vecchio, A, Wang, J, Wang, Y, You, X, Zhu, W, Zhu, X, High Energy Astrophys. & Astropart. Phys (API, FNWI), Cavendish Laboratory, University of Cambridge [UK] (CAM), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), University of California, University of California (UC), Max-Planck-Institut für Radioastronomie (MPIFR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), NASA Goddard Space Flight Center (GSFC), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Netherlands Institute for Radio Astronomy (ASTRON), Curtin University [Perth], Planning and Transport Research Centre (PATREC), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), National Radio Astronomy Observatory (NRAO), Center for Radiophysics and Space Research [Ithaca] (CRSR), Cornell University [New York], Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Department of Astronomy [Ithaca], Department of Physics, Hillsdale College, Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), University of British Columbia (UBC), Vancouver Coastal Health, Department of Nuclear Medicine, Netherlands Institute for Radio Astronomy ( ASTRON ), ARC Centre of Excellence for Coral Reef Studies (CoralCoE), James Cook University (JCU), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Vrije Universiteit Medical Centre (VUMC), Vrije Universiteit Amsterdam [Amsterdam] (VU), Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], National Radio Astronomy Observatory [Green Bank] (NRAO), Jodrell Bank Centre for Astrophysics (JBCA), Department of Physics, West Virginia University, West Virginia University, Theoretical Astrophysics [Pasadena] (TAPIR), California Institute of Technology (CALTECH), Physics Department, Lafayette College, Lafayette College [Easton], Department of Astronomy [Charlottesville], University of Virginia, APC - Gravitation (APC-Gravitation), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre for Astrophysics and Supercomputing [Swinburne] (CAS), Swinburne University of Technology [Melbourne], Anton Pannekoek Institute for Astronomy, University of Amsterdam [Amsterdam] (UvA), University of Wisconsin - Milwaukee, Department of Physics and Astronomy, University of British Columbia, Department of Physics and Astronomy [Oberlin], Oberlin College, Institute of Meteoritics [Albuquerque] (IOM), The University of New Mexico [Albuquerque], Department of Physics and Astronomy, West Virginia University, West Virginia University [Morgantown], Birmingham City University (BCU), Xinjiang Astronomical Observatory, Chinese Academy of Sciences [Beijing] (CAS), Huazhong University of Science and Technology [Wuhan] (HUST), School of Physical Science and Technology, Southwest University [Chongqing], Australian Research Council Discovery Project DP140102578NASA through Einstein Fellowship grant PF3-140116West Light Foundation of CAS XBBS201322 and NSFC project no.11403086National Science Fundation of China (NSFC) award number 11503007NNSF of China (U1231120) and FRFCU (XDJK2015B012), European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), European Project: 227947,EC:FP7:ERC,ERC-2008-AdG,LEAP(2009), European Project: 610058,EC:FP7:ERC,ERC-2013-SyG,BLACKHOLECAM(2014), Cornell University, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Division of Physics, Mathematics and Astronomy [Pasadena], California Institute of Technology (CALTECH)-California Institute of Technology (CALTECH), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), California Institute of Technology (CALTECH)-NASA, Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), University of Virginia [Charlottesville], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, data analysis, pulsars: general [methods], FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Methods: Data analysi, Astrophysics, Astronomy & Astrophysics, general [pulsars], 01 natural sciences, General Relativity and Quantum Cosmology, pulsars:individual, Binary pulsar, Pulsar, 0103 physical sciences, data analysis [methods], Coherence (signal processing), Sensitivity (control systems), Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Stochastic process, Noise (signal processing), Model selection, Pulsars: General, Astronomy and Astrophysics, methods: data analysis, LIGO, Computational physics, Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], 13. Climate action, Space and Planetary Science, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Astronomical and Space Sciences
Abstract: We analyse the stochastic properties of the 49 pulsars that comprise the first International Pulsar Timing Array (IPTA) data release. We use Bayesian methodology, performing model selection to determine the optimal description of the stochastic signals present in each pulsar. In addition to spin-noise and dispersion-measure (DM) variations, these models can include timing noise unique to a single observing system, or frequency band. We show the improved radio-frequency coverage and presence of overlapping data from different observing systems in the IPTA data set enables us to separate both system and band-dependent effects with much greater efficacy than in the individual PTA data sets. For example, we show that PSR J1643$-$1224 has, in addition to DM variations, significant band-dependent noise that is coherent between PTAs which we interpret as coming from time-variable scattering or refraction in the ionised interstellar medium. Failing to model these different contributions appropriately can dramatically alter the astrophysical interpretation of the stochastic signals observed in the residuals. In some cases, the spectral exponent of the spin noise signal can vary from 1.6 to 4 depending upon the model, which has direct implications for the long-term sensitivity of the pulsar to a stochastic gravitational-wave (GW) background. By using a more appropriate model, however, we can greatly improve a pulsar's sensitivity to GWs. For example, including system and band-dependent signals in the PSR J0437$-$4715 data set improves the upper limit on a fiducial GW background by $\sim 60\%$ compared to a model that includes DM variations and spin-noise only., Comment: 29 pages. 16 figures. Accepted for publication in MNRAS
Published: 2016
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16. The International Pulsar Timing Array: First data release

Author: Lucas Guillemot, Sourav Chatterjee, N. Garver-Daniels, D. R. Madison, Scott M. Ransom, J. K. Swiggum, Daniel R. Stinebring, Delphine Perrodin, Ingrid H. Stairs, Alberto Vecchio, Timothy Dolch, X. Siemens, Gregory Desvignes, Antoine Petiteau, Gilles Theureau, W. van Straten, J. B. Wang, X. P. You, Jason W. T. Hessels, Renée Spiewak, R. N. Caballero, Alberto Sesana, Stefan Oslowski, R. S. Lynch, Xing-Jiang Zhu, C. G. Bassa, Emmanuel Fonseca, Daniel J. Reardon, Yue-Fei Wang, Chiara M. F. Mingarelli, Benjamin Stappers, Kejia Lee, Stanislav Babak, Benetge Perera, Pablo Rosado, Zaven Arzoumanian, Richard N. Manchester, Paul Demorest, A. Brazier, Jonathan R. Gair, R. van Haasteren, Nipuni Palliyaguru, Lina Levin, R. Smits, Joseph Simon, P. Brem, Michele Vallisneri, Michael Kramer, James M. Cordes, Andrew Lyne, L. Lentati, Weiwei Zhu, Matthew Kerr, Peter A. Gentile, Michael Keith, A. Possenti, D. J. Champion, Caterina Tiburzi, T. J. W. Lazio, N. D. R. Bhat, A. Lassus, Stephen Taylor, Linqing Wen, Ryan Shannon, Glenn Jones, Shi Dai, E. Graikou, Gemma H. Janssen, S. J. Chamberlin, Kevin Stovall, Kang Liu, P. Lazarus, Ramesh Karuppusamy, S. A. Sanidas, Ismaël Cognard, George Hobbs, Robert D. Ferdman, Timothy T. Pennucci, M. Burgay, Sean T. McWilliams, David J. Nice, B. Christy, G. Shaifullah, L. Toomey, Justin A. Ellis, J. W. McKee, Maura McLaughlin, Paul D. Lasky, Michael T. Lam, Sarah Burke-Spolaor, Joris P. W. Verbiest, Marjorie Gonzalez, High Energy Astrophys. & Astropart. Phys (API, FNWI), Verbiest, J, Lentati, L, Hobbs, G, van Haasteren, R, Demorest, P, Janssen, G, Wang, J, Desvignes, G, Caballero, R, Keith, M, Champion, D, Arzoumanian, Z, Babak, S, Bassa, C, Bhat, N, Brazier, A, Brem, P, Burgay, M, Burke-Spolaor, S, Chamberlin, S, Chatterjee, S, Christy, B, Cognard, I, Cordes, J, Dai, S, Dolch, T, Ellis, J, Ferdman, R, Fonseca, E, Gair, J, Garver-Daniels, N, Gentile, P, Gonzalez, M, Graikou, E, Guillemot, L, Hessels, J, Jones, G, Karuppusamy, R, Kerr, M, Kramer, M, Lam, M, Lasky, P, Lassus, A, Lazarus, P, Lazio, T, Lee, K, Levin, L, Liu, K, Lynch, R, Lyne, A, Mckee, J, Mclaughlin, M, Mcwilliams, S, Madison, D, Manchester, R, Mingarelli, C, Nice, D, Osłowski, S, Palliyaguru, N, Pennucci, T, Perera, B, Perrodin, D, Possenti, A, Petiteau, A, Ransom, S, Reardon, D, Rosado, P, Sanidas, S, Sesana, A, Shaifullah, G, Shannon, R, Siemens, X, Simon, J, Smits, R, Spiewak, R, Stairs, I, Stappers, B, Stinebring, D, Stovall, K, Swiggum, J, Taylor, S, Theureau, G, Tiburzi, C, Toomey, L, Vallisneri, M, van Straten, W, Vecchio, A, Wang, Y, Wen, L, You, X, Zhu, W, Zhu, X, Max-Planck-Institut für Radioastronomie (MPIFR), Cavendish Laboratory, University of Cambridge [UK] (CAM), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), Netherlands Institute for Radio Astronomy (ASTRON), Xinjiang Astronomical Observatory, Chinese Academy of Sciences [Beijing] (CAS), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], NASA Goddard Space Flight Center (GSFC), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Curtin University [Perth], Planning and Transport Research Centre (PATREC), Cornell Center for Astrophysics and Planetary Science (CCAPS), Cornell University [New York], INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Pennsylvania State University (Penn State), Penn State System, Center for Radiophysics and Space Research [Ithaca] (CRSR), University of Maryland [College Park], University of Maryland System, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Department of Astronomy [Ithaca], Department of Physics, Hillsdale College, University of British Columbia (UBC), University of Edinburgh, Department of Physics and Astronomy, West Virginia University, West Virginia University [Morgantown], Vancouver Coastal Health, Department of Nuclear Medicine, Department of Physics, Columbia University, Columbia University [New York], Monash Centre for Astrophysics (MoCA), Monash University [Clayton], Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], National Radio Astronomy Observatory [Green Bank] (NRAO), Theoretical Astrophysics [Pasadena] (TAPIR), Division of Physics, Mathematics and Astronomy [Pasadena], California Institute of Technology (CALTECH)-California Institute of Technology (CALTECH), Physics Department, Lafayette College, Lafayette College [Easton], Physics Department, Texas Tech University, Texas Tech University [Lubbock] (TTU), Department of Astronomy [Charlottesville], University of Virginia [Charlottesville], APC - Gravitation (APC-Gravitation), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Centre for Astrophysics and Supercomputing [Swinburne] (CAS), Swinburne University of Technology [Melbourne], Anton Pannekoek Institute for Astronomy, University of Amsterdam [Amsterdam] (UvA), University of Wisconsin - Milwaukee, Center for Gravitation, Cosmology and Astrophysics, Netherlands Institute for Radio Astronomy ( ASTRON ), Department of Physics and Astronomy, University of British Columbia, Department of Physics and Astronomy [Oberlin], Oberlin College, Department of Physics and Astronomy [Albuquerque], The University of New Mexico [Albuquerque], Birmingham City University (BCU), School of Physics [HUST], Huazhong University of Science and Technology [Wuhan] (HUST), School of Physics (University of Western Australia), Université, School of Physical Science and Technology, Southwest University [Chongqing], European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), Max-Planck-Institut für Radioastronomie, Cavendish Laboratory - University of Cambridge, University of Cambridge [UK] ( CAM ), CSIRO Astronomy and Space Science, PO BOX 76, NSW 1710, Australia, Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), National Radio Astronomy Observatory [Socorro] ( NRAO ), National Radio Astronomy Observatory ( NRAO ), Netherlands Institute for Radio Astronomy, Chinese Academy of Sciences [Beijing] ( CAS ), NASA Goddard Space Flight Center ( GSFC ), Albert Einstein Institute, Max-Planck-Institut für Gravitationsphysik, Curtin University, Perth, Australia, Cornell Center for Astrophysics and Planetary Science ( CCAPS ), Cornell University, MPI for Gravitational Physics (Albert Einstein Institute), INAF-Osservatorio di Cagliari, PennState University [Pennsylvania] ( PSU ), Center for Radiophysics and Space Research [Ithaca] ( CRSR ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Unité Scientifique de la Station de Nançay ( USN ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), University of British Columbia ( UBC ), University of Edimburgh, Kavli Institute for Astronomy and Astrophysics, National Radio Astronomy Observatory [Green Bank] ( NRAO ), Commonwealth Scientific and Industrial Research Organisation [Canberra] ( CSIRO ), TAPIR (Theoretical Astrophysics), California Institute of Technology, Texas Tech University [Lubbock] ( TTU ), Osservatorio Astronomico di Cagliari, Ist Nazl Astrofis, Osservatorio Astronomico di Cagliari, APC - Gravitation ( APC-Gravitation ), AstroParticule et Cosmologie ( APC - UMR 7164 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Max-Planck-Institut für Gravitationsphysik (Albert-Einstein-Institut), Max-Planck-Institut-Max-Planck-Institut, Centre for Astrophysics and Supercomputing [Swinburne] ( CAS ), Anton Pannekoek Institute for Astronomy, University of Amsterdam, Max Planck Institut für Gravitationsphysik, Albert Einstein Institut, Physics and Astronomy Department [Oberlin], Center for Gravitational Wave Astronomy, The University of Texas at Brownsville and Texas Southmost College, Birmingham City University ( BCU ), School of Physics, Huazhong University of Science and Technology, Huazhong University of Science and Technology, School of Physics ( University of Western Australia ), European Project : 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET ( 2014 ), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), University of Virginia, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI)
Subjects: data analysis, data analysis, pulsars: general [methods], FOS: Physical sciences, Methods: Data analysi, general [pulsars], 01 natural sciences, 7. Clean energy, Set (abstract data type), Pulsar timing array, Pulsar, 0103 physical sciences, data analysis [methods], Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, instrumentation, Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Pulsars: General, Astronomy, Astronomy and Astrophysics, methods: data analysis, Data set, European Pulsar Timing Array, Neutron star, gravitational waves, Space and Planetary Science, pulsars, Measurement uncertainty, Astrophysics - Instrumentation and Methods for Astrophysics, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Algorithm, astro-ph.IM
Abstract: The highly stable spin of neutron stars can be exploited for a variety of (astro-)physical investigations. In particular arrays of pulsars with rotational periods of the order of milliseconds can be used to detect correlated signals such as those caused by gravitational waves. Three such "Pulsar Timing Arrays" (PTAs) have been set up around the world over the past decades and collectively form the "International" PTA (IPTA). In this paper, we describe the first joint analysis of the data from the three regional PTAs, i.e. of the first IPTA data set. We describe the available PTA data, the approach presently followed for its combination and suggest improvements for future PTA research. Particular attention is paid to subtle details (such as underestimation of measurement uncertainty and long-period noise) that have often been ignored but which become important in this unprecedentedly large and inhomogeneous data set. We identify and describe in detail several factors that complicate IPTA research and provide recommendations for future pulsar timing efforts. The first IPTA data release presented here (and available online) is used to demonstrate the IPTA's potential of improving upon gravitational-wave limits placed by individual PTAs by a factor of ~2 and provides a 2-sigma limit on the dimensionless amplitude of a stochastic GWB of 1.7x10^{-15} at a frequency of 1 yr^{-1}. This is 1.7 times less constraining than the limit placed by (Shannon et al. 2015), due mostly to the more recent, high-quality data they used., 25 pages, 6 tables, 5 figures. Accepted for publication in MNRAS
Published: 2016
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17. The host galaxy of a fast radio burst

Author: Mansi M. Kasliwal, Andrew Jameson, Tsuyoshi Terai, Naoki Yasuda, N. D. R. Bhat, Andrew Williams, Poonam Chandra, Ralph Eatough, W. van Straten, Delphine Perrodin, Yuu Niino, E. D. Barr, Matthew Bailes, Steven Tingay, M. Burgay, M. Caleb, Tomoki Morokuma, Hajime Sugai, Evan Keane, Jacob E. Jencson, Ben Stappers, Shotaro Yamasaki, Takashi Hattori, A. Possenti, Mitchell B. Mickaliger, Randall B. Wayth, Michael Kramer, Jeff Cooke, M. Berezina, Mareki Honma, Tomonori Totani, C. G. Bassa, R. Allen, David L. Kaplan, Shivani Bhandari, Nozomu Tominaga, Simon Johnston, Hisanori Furusawa, E. Petroff, Sarah Burke-Spolaor, and Chris Flynn
Subjects: Physics, Multidisciplinary, 010308 nuclear & particles physics, Radio galaxy, Fast radio burst, Astrophysics::High Energy Astrophysical Phenomena, Canadian Hydrogen Intensity Mapping Experiment, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Redshift survey, 01 natural sciences, Redshift, Galaxy, Interstellar medium, X-shaped radio galaxy, 0103 physical sciences, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy’s redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called ‘missing baryons’. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.
Published: 2016
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18. Improving timing sensitivity in the microhertz frequency regime: limits from PSR J1713$+$0747 on gravitational waves produced by super-massive black-hole binaries

Author: John Antoniadis, Gregory Desvignes, R. N. Caballero, Benjamin Stappers, Gilles Theureau, James Mckee, G. Shaifullah, E. Graikou, Andrew Lyne, Cees Bassa, Stefan Oslowski, Sotirios A. Sanidas, L. Lentati, Lucas Guillemot, Benetge Perera, Ramesh Karuppusamy, Ismaël Cognard, Michael Kramer, Delphine Perrodin, Joris P. W. Verbiest, Stephen Taylor, Michael Keith, Kang Liu, P. Lazarus, Gemma H. Janssen, Alberto Sesana, S Babak, D. J. Champion, AstroParticule et Cosmologie ( APC - UMR 7164 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Unité Scientifique de la Station de Nançay ( USN ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Univers et Théories ( LUTH ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), ITA, USA, GBR, FRA, DEU, AUS, NLD, RUS, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Perera, B, Stappers, B, Babak, S, Keith, M, Antoniadis, J, Bassa, C, Caballero, R, Champion, D, Cognard, I, Desvignes, G, Graikou, E, Guillemot, L, Janssen, G, Karuppusamy, R, Kramer, M, Lazarus, P, Lentati, L, Liu, K, Lyne, A, Mckee, J, Osłowski, S, Perrodin, D, Sanidas, S, Sesana, A, Shaifullah, G, Theureau, G, Verbiest, J, Taylor, S, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], FOS: Physical sciences, Astrophysics, 01 natural sciences, Bayesian, stars: neutron, neutron, Pulsar, Millisecond pulsar, 0103 physical sciences, Quasars: Supermassive black hole, black hole, 010303 astronomy & astrophysics, orbit, quasars: supermassive, pulsar, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Supermassive black hole, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Gravitational wave, stars, quasars: supermassive black holes, Astrophysics::Instrumentation and Methods for Astrophysics, gravitational radiation, Astronomy and Astrophysics, sensitivity, black holes, Black hole, Orbit, European Pulsar Timing Array, Amplitude, binaries: general, gravitational waves, black hole: binary, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], frequency, spectral, Stars: Black hole, pulsars: individual: PSR J1713+0747, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], stars: black holes
Abstract: We search for continuous gravitational waves (CGWs) produced by individual super-massive black-hole binaries (SMBHBs) in circular orbits using high-cadence timing observations of PSR J1713$+$0747. We observe this millisecond pulsar using the telescopes in the European Pulsar Timing Array (EPTA) with an average cadence of approximately 1.6 days over the period between April 2011 and July 2015, including an approximately daily average between February 2013 and April 2014. The high-cadence observations are used to improve the pulsar timing sensitivity across the GW frequency range of $0.008-5$ $\mu$Hz. We use two algorithms in the analysis, including a spectral fitting method and a Bayesian approach. For an independent comparison, we also use a previously published Bayesian algorithm. We find that the Bayesian approaches provide optimal results and the timing observations of the pulsar place a 95 per cent upper limit on the sky-averaged strain amplitude of CGWs to be $\lesssim3.5\times10^{-13}$ at a reference frequency of 1 $\mu$Hz. We also find a 95 per cent upper limit on the sky-averaged strain amplitude of low-frequency CGWs to be $\lesssim1.4\times10^{-14}$ at a reference frequency of 20~nHz., Comment: 12 pages, 4 figures. Accepted for publication in MNRAS
Published: 2018
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19. The SUrvey for Pulsars and Extragalactic Radio Bursts – II. New FRB discoveries and their follow-up

Author: Matthew Bailes, T. A. Pritchard, Mitchell B. Mickaliger, A. Trovato, C. Lachaud, Maurizio Spurio, A.J. Heijboer, M. Anghinolfi, N. El Khayati, Ivan Felis, Daniele Vivolo, S. Loucatos, Utane Sawangwit, M. Marcelin, R. Coniglione, Paolo Sapienza, A. Klotz, J. Zúñiga, S.F. Biagi, Dominique Lefèvre, Jörn Wilms, J. Hofestädt, Alba Domi, C. Racca, Silvia Celli, D. Dornic, S. Basa, M. de Jong, I. El Bojaddaini, A. Marinelli, V. Popa, Dominik Elsässer, Tomonori Totani, V. Bertin, M. Circella, Timothée Grégoire, A. Ettahiri, A. Sánchez-Losa, C. Pellegrino, Anne Deschamps, Yann Hello, Matteo Sanguineti, Eric Howell, Steffen Hallmann, J. Carr, Annarita Margiotta, Antoine Kouchner, M. Saldaña, M.C. Bouwhuis, J. A. Green, Michel André, F. Schüssler, I. Salvadori, D. Turpin, Paolo Piattelli, R. Bormuth, Thomas Eberl, Sarah Burke-Spolaor, Richard Wilson, R. Mele, C. Perrina, Alessandro Corongiu, Tommaso Chiarusi, G.E. Păvălaş, Hervé Glotin, V. Van Elewyck, J. Busto, Pablo Torne, P. Jaroenjittichai, E. Petroff, E. Nezri, V. Venkatraman Krishnan, M. Jongen, V. Morello, P. Migliozzi, A. Creusot, G. De Bonis, Joao Coelho, R. Bruijn, J. Hößl, T. Avgitas, Jürgen Brunner, D. Kießling, Federico Versari, M. Organokov, C. Distefano, Juan José Hernández-Rey, O. Kalekin, D. F. E. Samtleben, M. Taiuti, C. Tönnis, A. Enzenhöfer, Giulia Illuminati, I. Di Palma, J.A. Martínez-Mora, Alexis Coleiro, M. Caleb, C. Hugon, C. Sieger, Michael Kramer, H. Brânzaş, J-J. Aubert, Emanuele Leonora, Antonio F. Díaz, P. Coyle, Poonam Chandra, L. Caramete, Giorgio Riccobene, F. Jankowski, Richard Dodson, Th. Stolarczyk, J.D. Zornoza, B. Vallage, Alessio Trois, Vladimir Kulikovskiy, Miguel Ardid, B. Belhorma, Chris Flynn, M. Kreter, Gisela Anton, A. Jameson, A. Vizzocca, V. Giordano, A. Capone, H. van Haren, Timothy Butterley, T. Pradier, R. Cherkaoui El Moursli, Evan Keane, S. Bourret, Ralph Eatough, David Coward, W. van Straten, S. Navas, Delphine Perrodin, U. F. Katz, V. S. Dhillon, Farida Fassi, I. Andreoni, E. D. Barr, C. W. James, Kay Graf, Karel Melis, Jeff Cooke, S. P. Littlefair, Arnauld Albert, Caterina Tiburzi, T. R. Marsh, N. D. R. Bhat, L. K. Hardy, Abdelilah Moussa, Doriane Drouhin, Benjamin Stappers, I. Kreykenbohm, Yuu Niino, Bruny Baret, Simon Johnston, Robert Lahmann, A. Possenti, L. Quinn, Shivani Bhandari, Nozomu Tominaga, Yahya Tayalati, R. Gracia-Ruiz, Tsuyoshi Terai, H. Costantini, J. Barrios-Martí, Luigi Antonio Fusco, Matthias Kadler, T. Michael, T. W. B. Muxlow, M. Burgay, C. Donzaud, Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Groupe de Recherche en Physique des Hautes Energies (GRPHE), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut Universitaire de Technologie de Colmar, Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11), Laboratoire de Physique de Clermont (LPC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Laboratoire des Sciences de l'Information et des Systèmes (LSIS), Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Université de Toulon (UTLN)-Aix Marseille Université (AMU), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Institut méditerranéen d'océanologie (MIO), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Département de Physique des Particules (ex SPP) (DPP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien (IPHC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), ANTARES, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Arts et Métiers Paristech ENSAM Aix-en-Provence-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Toulon (UTLN)-Aix Marseille Université (AMU)-Institut de Recherche pour le Développement (IRD), Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-IUT de Colmar, Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Département de Physique des Particules (ex SPP) (DPhP), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Physique des Particules de Marseille ( CPPM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Aix Marseille Université ( AMU ), AstroParticule et Cosmologie ( APC - UMR 7164 ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Laboratoire d'Astrophysique de Marseille ( LAM ), Aix Marseille Université ( AMU ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Observatoire de la Côte d'Azur ( OCA ), Centre National de la Recherche Scientifique ( CNRS ), Université Paris-Sud - Paris 11 ( UP11 ), Laboratoire de Physique de Clermont ( LPC ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire des Sciences de l'Information et des Systèmes ( LSIS ), Aix Marseille Université ( AMU ) -Université de Toulon ( UTLN ) -Arts et Métiers Paristech ENSAM Aix-en-Provence-Centre National de la Recherche Scientifique ( CNRS ), Institut méditerranéen d'océanologie ( MIO ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Toulon ( UTLN ) -Aix Marseille Université ( AMU ) -Institut de Recherche pour le Développement ( IRD ), Département de Physique des Particules (ex SPP) ( DPP ), Institut de Recherches sur les lois Fondamentales de l'Univers ( IRFU ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Paris-Saclay, Institut Pluridisciplinaire Hubert Curien ( IPHC ), Centre National de la Recherche Scientifique ( CNRS ) -Université de Strasbourg ( UNISTRA ), Centre Tecnològic de Vilanova i la Geltrú, Universitat Politècnica de Catalunya. LAB - Laboratori d'Aplicacions Bioacústiques, Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), KM3NeT (IHEF, IoP, FNWI), Bhandari, S, Keane, Ef, Barr, Ed, Jameson, A, Petroff, E, Johnston, S, Bailes, M, Bhat, Ndr, Burgay, M, Burke-Spolaor, S, Caleb, M, Eatough, Rp, Flynn, C, Green, Ja, Jankowski, F, Kramer, M, Krishnan, Vv, Morello, V, Possenti, A, Stappers, B, Tiburzi, C, van Straten, W, Andreoni, I, Butterley, T, Chandra, P, Cooke, J, Corongiu, A, Coward, Dm, Dhillon, V, Dodson, R, Hardy, Lk, Howell, Ej, Jaroenjittichai, P, Klotz, A, Littlefair, Sp, Marsh, Tr, Mickaliger, M, Muxlow, T, Perrodin, D, Pritchard, T, Sawangwit, U, Terai, T, Tominaga, N, Torne, P, Totani, T, Trois, A, Turpin, D, Niino, Y, Wilson, Rw, Albert, A, Andre, M, Anghinolfi, M, Anton, G, Ardid, M, Aubert, Jj, Avgitas, T, Baret, B, Barrios-Marti, J, Basa, S, Belhorma, B, Bertin, V, Biagi, S, Bormuth, R, Bourret, S, Bouwhuis, Mc, Branzas, H, Bruijn, R, Brunner, J, Busto, J, Capone, A, Caramete, L, Carr, J, Celli, S, El Moursli, Rc, Chiarusi, T, Circella, M, Coelho, Jab, Coleiro, A, Coniglione, R, Costantini, H, Coyle, P, Creusot, A, Diaz, Af, Deschamps, A, De Bonis, G, Distefano, C, Di Palma, I, Domi, A, Donzaud, C, Dornic, D, Drouhin, D, Eberl, T, El Bojaddaini, I, Khayati, N, Elasser, D, Enzenhoefer, A, Ettahiri, A, Fassi, F, Felis, I, Fusco, La, Gay, P, Giordano, V, Glotin, H, Gregoire, T, Gracia-Ruiz, R, Graf, K, Hallmann, S, van Haren, H, Heijboer, Aj, Hello, Y, Hernandez-Rey, Jj, Hossl, J, Hofestadt, J, Hugon, C, Illuminati, G, James, Cw, de Jong, M, Jongen, M, Kadler, M, Kalekin, O, Katz, U, Kiessling, D, Kouchner, A, Kreter, M, Kreykenbohm, I, Kulikovskiy, V, Lachaud, C, Lahmann, R, Lefevere, D, Leonora, E, Loucatos, S, Marcelin, M, Margiotta, A, Marinelli, A, Martinez-Mora, Ja, Mele, R, Melis, K, Michael, T, Migliozzi, P, Moussa, A, Navas, S, Nezri, E, Organokov, M, Pavalas, Ge, Pellegrino, C, Perrina, C, Piattelli, P, Popa, V, Pradier, T, Quinn, L, Racca, C, Riccobene, G, Sanchez-Losa, A, Saldana, M, Salvadori, I, Samtleben, Dfe, Sanguineti, M, Sapienza, P, Schussler, F, Sieger, C, Spurio, M, Stolarczyk, T, Taiuti, M, Tayalati, Y, Trovato, A, Tonnis, C, Vallage, B, Van Elewyck, V, Versari, F, Vivolo, D, Vizzocca, A, Wilms, J, Zornoza, Jd, Zuniga, J, Bhandari, S., Keane, E.F., Barr, E.D., Jameson, A., Petroff, E., Johnston, S., Bailes, M., Bhat, N.D.R., Burgay, M., Burke-Spolaor, S., Caleb, M., Eatough, R.P., Flynn, C., Green, J.A., Jankowski, F., Kramer, M., Venkatraman Krishnan, V., Morello, V., Possenti, A., Stappers, B., Tiburzi, C., van Straten, W., Andreoni, I., Butterley, T., Chandra, P., Cooke, J., Corongiu, A., Coward, D.M., Dhillon, V.S., Dodson, R., Hardy, L.K., Howell, E.J., Jaroenjittichai, P., Klotz, A., Littlefair, S.P., Marsh, T.R., Mickaliger, M., Muxlow, T., Perrodin, D., Pritchard, T., Sawangwit, U., Terai, T., Tominaga, N., Torne, P., Totani, T., Trois, A., Turpin, D., Niino, Y., Wilson, R.W., Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., Avgitas, T., Baret, B., Barrios-Martí, J., Basa, S., Belhorma, B., Bertin, V., Biagi, S., Bormuth, R., Bourret, S., Bouwhuis, M.C., Brănzas, H., Bruijn, R., Brunner, J., Busto, J., Capone, A., Caramete, L., Carr, J., Celli, S., El Moursli, R. Cherkaoui, Chiarusi, T., Circella, M., Coelho, J.A.B., Coleiro, A., Coniglione, R., Costantini, H., Coyle, P., Creusot, A., Díaz, A.F., Deschamps, A., De Bonis, G., Distefano, C., Di Palma, I., Domi, A., Donzaud, C., Dornic, D., Drouhin, D., Eberl, T., El Bojaddaini, I., El Khayati, N., Elsässer, D., Enzenhöfer, A., Ettahiri, A., Fassi, F., Felis, I., Fusco, L.A., Gay, P., Giordano, V., Glotin, H., Gregoire, T., Gracia-Ruiz, R., Graf, K., Hallmann, S., van Haren, H., Heijboer, A.J., Hello, Y., Hernández-Rey, J.J., Hößl, J., Hofestädt, J., Hugon, C., Illuminati, G., James, C.W., de Jong, M., Jongen, M., Kadler, M., Kalekin, O., Katz, U., Kießling, D., Kouchner, A., Kreter, M., Kreykenbohm, I., Kulikovskiy, V., Lachaud, C., Lahmann, R., Lefevre, D., Leonora, E., Loucatos, S., Marcelin, M., Margiotta, A., Marinelli, A., Martínez-Mora, J.A., Mele, R., Melis, K., Michael, T., Migliozzi, P., Moussa, A., Navas, S., Nezri, E., Organokov, M., Pavalas, G.E., Pellegrino, C., Perrina, C., Piattelli, P., Popa, V., Pradier, T., Quinn, L., Racca, C., Riccobene, G., Sánchez-Losa, A., Saldana, M., Salvadori, I., Samtleben, D.F.E., Sanguineti, M., Sapienza, P., Schüssler, F., Sieger, C., Spurio, M., Stolarczyk, Th., Taiuti, M., Tayalati, Y., Trovato, A., Tönnis, C., Vallage, B., Van Elewyck, V., Versari, F., Vivolo, D., Vizzocca, A., Wilms, J., Zornoza, J.D., Zúniga, J., Keane, E. F., Barr, E. D., Bhat, N. D. R., Eatough, R. P., Green, J. A., Coward, D. M., Dhillon, V. S., Hardy, L. K., Howell, E. J., Littlefair, S. P., Marsh, T. R., Wilson, R. W., Andre, M., Aubert, J. -J., Barrios-Marti, J., Bouwhuis, M. C., Branzas, H., El Moursli, R. C., Coelho, J. A. B., Diaz, A. F., Elsasser, D., Enzenhofer, A., Fusco, L. A., Heijboer, A. J., Hernandez-Rey, J. J., Hossl, J., Hofestadt, J., James, C. W., Kiessling, D., Martinez-Mora, J. A., Pavalas, G. E., Sanchez-Losa, A., Samtleben, D. F. E., Schussler, F., Stolarczyk, T., Tonnis, C., Zornoza, J. D., and Zuniga, J.
Subjects: surveys – intergalactic medium, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], data analysis, Astrophysics, Surveys, 7. Clean energy, 01 natural sciences, radiation mechanisms, observational surveys, intergalactic medium, radio continuum, Astronomical observatories, Methods: Data analysis, Survey, data analysis [Methods], 010303 astronomy & astrophysics, media_common, general [Radiation mechanisms], Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Fast radio burst, general [Radio continuum], Canadian Hydrogen Intensity Mapping Experiment, Intergalactic medium, Methods: Observational, Radiation mechanisms: General, Radio continuum: General, Neutrino, Observatoris astronòmics, Astrophysics - High Energy Astrophysical Phenomena, general [adio continuum], media_common.quotation_subject, FOS: Physical sciences, Methods: Data analysi, Radio telescope, Pulsar, 0103 physical sciences, Radiation mechanisms, observational [Methods], Source counts, Telescopis, Astronomy and Astrophysics, Space and Planetary Science, 010308 nuclear & particles physics, radiation mechanisms: general, methods: data analysis, methods: observational, radio continuum: general, Astronomy, Astronomy and Astrophysic, Afterglow, Radio continuum, 13. Climate action, Sky, FISICA APLICADA, Física::Astronomia i astrofísica [Àrees temàtiques de la UPC], data analysi [methods], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Telescopes
Abstract: SB would like to thank Tara Murphy, Martin Bell, Paul Hancock, Keith Bannister, Chris Blake and Bing Zhang for useful discussions., We report the discovery of four Fast Radio Bursts (FRBs) in the ongoing SUrvey for Pulsars and Extragalactic Radio Bursts at the Parkes Radio Telescope: FRBs 150610, 151206, 151230 and 160102. Our real-time discoveries have enabled us to conduct extensive, rapid multimessenger follow-up at 12 major facilities sensitive to radio, optical, X-ray, gamma-ray photons and neutrinos on time-scales ranging from an hour to a few months post-burst. No counterparts to the FRBs were found and we provide upper limits on afterglow luminosities. None of the FRBs were seen to repeat. Formal fits to all FRBs show hints of scattering while their intrinsic widths are unresolved in time. FRB 151206 is at low Galactic latitude, FRB 151230 shows a sharp spectral cut-off, and FRB 160102 has the highest dispersion measure (DM = 2596.1 ± 0.3 pc cm−3) detected to date. Three of the FRBs have high dispersion measures (DM > 1500 pc cm−3), favouring a scenario where the DM is dominated by contributions from the intergalactic medium. The slope of the Parkes FRB source counts distribution with fluences >2 Jy ms is α=−2.2+0.6−1.2 and still consistent with a Euclidean distribution (α = −3/2). We also find that the all-sky rate is 1.7+1.5−0.9×103 FRBs/(4π sr)/day above ∼2Jyms and there is currently no strong evidence for a latitude-dependent FRB sky rate., The Parkes radio telescope and the Australia Telescope Compact Array are part of the Australia Telescope National Facility which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. Parts of this research were conducted by the Australian Research Council Centre of Excellence for All-sky Astrophysics (CAASTRO), through project number CE110001020. The GMRT is run by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research. VLAis run by theNational Radio Astronomy Observatory (NRAO). NRAO is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. This work was performed on the gSTAR national facility at Swinburne University of Technology. gSTAR is funded by Swinburne and the Australian Government’s Education Investment Fund. This work is also based on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. We thank the LSST Project for making their code available as free software at http://dm.lsstcorp.org. Funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. 617199 (EP). Access to the Lovell Telescope is supported through an STFC consolidated grant. The 100-m telescope in Effelsberg is operation by the Max- Planck-Institut für Radioastronomie with funds of the Max-Planck Society. The Sardinia Radio Telescope (SRT) is funded by the Department of University and Research (MIUR), the Italian Space Agency (ASI), and the Autonomous Region of Sardinia (RAS) and is operated as National Facility by the National Institute for Astrophysics (INAF). TB and RWW are grateful to the STFC for financial support (grant reference ST/P000541/1). Research support to IA is provided by the Australian Astronomical Observatory. The ANTARES authors acknowledge the financial support of the funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat à l’énergie atomique et aux énergies alternatives (CEA), Commission Européenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cité (ANR-10- LABX-0023 and ANR-11-IDEX-0005-02), Labex OCEVU (ANR- 11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001- 02), Région Île-de-France (DIM-ACAV), Région Alsace (contrat CPER), Région Provence-Alpes-Côte d’Azur, Département du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium für Bildung und Forschung (BMBF), Germany; IstitutoNazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economía y Competitividad (MINECO): Plan Estatal de Investigación (refs. FPA2015- 65150-C3-1-P, -2-P and -3-P, (MINECO/FEDER)), Severo Ochoa Centre of Excellence and MultiDark Consolider (MINECO), and Prometeo and Grisolía programs (Generalitat Valenciana), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge the technical support of Ifremer, AIM and Foselev Marine for the sea operation and the CC-IN2P3 for the computing facilities. This work made use of data supplied by the UK Swift Science Data Centre at the University of Leicester. This research has made use of data, software and/or web tools obtained from the High Energy Astrophysics Science Archive Research Center (HEASARC), a service of the Astrophysics Science Division at NASA/GSFC and of the Smithsonian Astrophysical Observatory’s High Energy Astrophysics Division. This work is based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. This paper makes use of software developed for the Large Synoptic Survey Telescope. We thank the LSST Project for making their code available as free software at http://dm.lsstcorp.org. RPE/MK gratefully acknowledges support from ERC Synergy Grant "BlackHoleCam" Grant Agreement Number 610058
Published: 2018
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20. Studying the Solar system with the International Pulsar Timing Array

Author: R. S. Lynch, L. Toomey, Paul Demorest, J. K. Swiggum, X. Siemens, Gregory Desvignes, A. Possenti, T. J. W. Lazio, Gilles Theureau, D. R. Madison, Lucas Guillemot, Joseph Simon, Renée Spiewak, Kejia Lee, Alberto Sesana, Andrea N. Lommen, Gemma H. Janssen, Ramesh Karuppusamy, Xing-Jiang Zhu, Ismaël Cognard, Chiara M. F. Mingarelli, Benjamin Stappers, Stefan Oslowski, Sean T. McWilliams, Scott M. Ransom, S. A. Sanidas, David J. Nice, Kang Liu, G. Shaifullah, Marjorie Gonzalez, Y J Guo, Caterina Tiburzi, Robert D. Ferdman, James M. Cordes, P. Lazarus, N. D. R. Bhat, Jonathan R. Gair, Daniel R. Stinebring, George Hobbs, Sarah Burke-Spolaor, Nipuni Palliyaguru, Benetge Perera, Daniel J. Reardon, Richard N. Manchester, Shi Dai, Michael Kramer, Ryan Shannon, A. Brazier, R. van Haasteren, Joris P. W. Verbiest, Zaven Arzoumanian, M. Burgay, Timothy T. Pennucci, W. van Straten, Lina Levin, K. Plant, Ingrid H. Stairs, Peter A. Gentile, Duncan R. Lorimer, E. Graikou, Weiwei Zhu, N. Garver-Daniels, D. J. Champion, Matthew Bailes, S. J. Chamberlin, Delphine Perrodin, Sourav Chatterjee, Kevin Stovall, Michael Keith, Matthew Kerr, Timothy Dolch, J. B. Wang, R. N. Caballero, C. G. Bassa, Emmanuel Fonseca, Michael T. Lam, Stephen Taylor, Paul D. Lasky, J. W. McKee, Maura McLaughlin, Laboratoire de physique et chimie de l'environnement (LPCE), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS), Caballero, R, Guo, Y, Lee, K, Lazarus, P, Champion, D, Desvignes, G, Kramer, M, Plant, K, Arzoumanian, Z, Bailes, M, Bassa, C, Bhat, N, Brazier, A, Burgay, M, Burke-Spolaor, S, Chamberlin, S, Chatterjee, S, Cognard, I, Cordes, J, Dai, S, Demorest, P, Dolch, T, Ferdman, R, Fonseca, E, Gair, J, Garver-Daniels, N, Gentile, P, Gonzalez, M, Graikou, E, Guillemot, L, Hobbs, G, Janssen, G, Karuppusamy, R, Keith, M, Kerr, M, Lam, M, Lasky, P, Lazio, T, Levin, L, Liu, K, Lommen, A, Lorimer, D, Lynch, R, Madison, D, Manchester, R, Mckee, J, Mclaughlin, M, Mcwilliams, S, Mingarelli, C, Nice, D, Osłowski, S, Palliyaguru, N, Pennucci, T, Perera, B, Perrodin, D, Possenti, A, Ransom, S, Reardon, D, Sanidas, S, Sesana, A, Shaifullah, G, Shannon, R, Siemens, X, Simon, J, Spiewak, R, Stairs, I, Stappers, B, Stinebring, D, Stovall, K, Swiggum, J, Taylor, S, Theureau, G, Tiburzi, C, Toomey, L, van Haasteren, R, van Straten, W, Verbiest, J, Wang, J, Zhu, X, and Zhu, W
Subjects: Solar System, Dwarf planet, FOS: Physical sciences, Astrophysics, Ephemeris, 01 natural sciences, Jovian, Pulsar, pulsars: general, 0103 physical sciences, Sensitivity (control systems), ephemerides, 010303 astronomy & astrophysics, Physics, Earth and Planetary Astrophysics (astro-ph.EP), methods: statistical, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Astronomy and Astrophysics, Planetary system, Ephemeride, methods: data analysis, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Methods: data analysi, Reference frame, Astrophysics - Earth and Planetary Astrophysics
Abstract: Pulsar-timing analyses are sensitive to errors in the solar-system ephemerides (SSEs) that timing models utilise to estimate the location of the solar-system barycentre, the quasi-inertial reference frame to which all recorded pulse times-of-arrival are referred. Any error in the SSE will affect all pulsars, therefore pulsar timing arrays (PTAs) are a suitable tool to search for such errors and impose independent constraints on relevant physical parameters. We employ the first data release of the International Pulsar Timing Array to constrain the masses of the planet-moons systems and to search for possible unmodelled objects (UMOs) in the solar system. We employ ten SSEs from two independent research groups, derive and compare mass constraints of planetary systems, and derive the first PTA mass constraints on asteroid-belt objects. Constraints on planetary-system masses have been improved by factors of up to 20 from the previous relevant study using the same assumptions, with the mass of the Jovian system measured at 9.5479189(3)$\times10^{-4}$ $M_{\odot}$. The mass of the dwarf planet Ceres is measured at 4.7(4)$\times10^{-10}$ $M_{\odot}$. We also present the first sensitivity curves using real data that place generic limits on the masses of UMOs, which can also be used as upper limits on the mass of putative exotic objects. For example, upper limits on dark-matter clumps are comparable to published limits using independent methods. While the constraints on planetary masses derived with all employed SSEs are consistent, we note and discuss differences in the associated timing residuals and UMO sensitivity curves., Comment: Accepted for publication by the Monthly Notices of the Royal Astronomical Society
Published: 2018
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21. Sardinia Roach2-based Digital Architecture for Radio Astronomy (SARDARA)

Author: Matteo Murgia, M. N. Iacolina, A. Bocchinu, I. Porceddu, E. Egron, P. Marongiu, Delphine Perrodin, Silvia Leurini, A. Casula, Pietro Bolli, Paolo Maxia, N. D'Amico, Giambattista Aresu, Paola Castangia, Andrea Possenti, Raimondo Concu, Andrea Melis, S. Casu, S. Loru, C. Cecchi Pestellini, Andrea Tarchi, Giuseppe Mazzarella, Matteo Bachetti, Alessandro Corongiu, A. Poddighe, G. Valente, Carlo Migoni, Maura Pilia, V. Vacca, Ettore Carretti, Alessio Trois, G. P. Vargiu, Giorgio Montisci, A. Ladu, F. Loi, Tonino Pisanu, M. Burgay, Federica Govoni, A. Pellizzoni, Massimo Barbaro, Sergio Poppi, and ITA
Subjects: Engineering, 010308 nuclear & particles physics, business.industry, Astronomy and Astrophysics, Digital architecture, 01 natural sciences, Radio telescope, 0103 physical sciences, Instrumentation (computer programming), business, 010303 astronomy & astrophysics, Instrumentation, Radio astronomy, Remote sensing
Abstract: The Sardinia Radio Telescope (SRT) is a 64-m, fully-steerable single-dish radio telescope that was recently commissioned both technically and scientifically with regard to the basic observing modes. In order to improve the scientific capability and cover all the requirements for an advanced single-dish radio telescope, we developed the SArdinia Roach2-based Digital Architecture for Radio Astronomy (SARDARA), a wide-band, multi-feed, general-purpose, and reconfigurable digital platform, whose preliminary setup was used in the early science program of the SRT in 2016. In this paper, we describe the backend both in terms of its scientific motivation and technical design, how it has been interfaced with the telescope environment during its development and, finally, its scientific commissioning in different observing modes with single-feed receivers.
Published: 2018

22. European Pulsar Timing Array limits on an isotropic stochastic gravitational-wave background

Author: Pablo Rosado, Chiara M. F. Mingarelli, Lucas Guillemot, Rutger van Haasteren, S. Sanidas, P. Brem, A. Lassus, M. B. Purver, Stanislav Babak, Cees Bassa, Jason W. T. Hessels, R. Smits, Antoine Petiteau, Alberto Vecchio, Ramesh Karuppusamy, D. J. Champion, Ismaël Cognard, Kejia Lee, Caterina Tiburzi, Andrea Possenti, Marta Burgay, P. Lazarus, Alberto Sesana, Lindley Lentati, Stefan Oslowski, Gemma H. Janssen, Stephen Taylor, Gregory Desvignes, Gilles Theureau, Joris P. W. Verbiest, Ben Stappers, Michael Kramer, R. Nicolas Caballero, Kuo Liu, Delphine Perrodin, Jonathan R. Gair, Cavendish Laboratory, University of Cambridge [UK] (CAM), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Birmingham City University (BCU), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Max-Planck-Institut für Radioastronomie (MPIFR), Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Netherlands Institute for Radio Astronomy (ASTRON), University of Amsterdam [Amsterdam] (UvA), Columbia Astrophysics Laboratory (CAL), Columbia University [New York], AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Universität Bielefeld, Centre for Astrophysics and Supercomputing, Swinburne University of Technology [Melbourne], Netherlands Institute for Radio Astronomy ( ASTRON ), 'Programme National de Cosmologie and Galaxies' (PNCG) of CNRS/INSU, France, European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), European Project: 610058,EC:FP7:ERC,ERC-2013-SyG,BLACKHOLECAM(2014), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Lentati, L, Taylor, S, Mingarelli, C, Sesana, A, Sanidas, S, Vecchio, A, Caballero, R, Lee, K, van Haasteren, R, Babak, S, Bassa, C, Brem, P, Burgay, M, Champion, D, Cognard, I, Desvignes, G, Gair, J, Guillemot, L, Hessels, J, Janssen, G, Karuppusamy, R, Kramer, M, Lassus, A, Lazarus, P, Liu, K, Oslowski, S, Perrodin, D, Petiteau, A, Possenti, A, Purver, M, Rosado, P, Smits, R, Stappers, B, Theureau, G, Tiburzi, C, Verbiest, J, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), High Energy Astrophys. & Astropart. Phys (API, FNWI), and API (FNWI)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, Cosmic microwave background, Cosmic background radiation, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Gravitational wave background, Pulsar timing array, gravitational waves methods: data analysis pulsars: general, Pulsar, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, Spectral index, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Gravitational wave, Spectral density, Astronomy and Astrophysics, Pulsars: general, Space and Planetary Science, astro-ph.CO, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics, Methods: data analysi, astro-ph.IM
Abstract: We present new limits on an isotropic stochastic gravitational-wave background (GWB) using a six pulsar dataset spanning 18 yr of observations from the 2015 European Pulsar Timing Array data release. Performing a Bayesian analysis, we fit simultaneously for the intrinsic noise parameters for each pulsar, along with common correlated signals including clock, and Solar System ephemeris errors, obtaining a robust 95$\%$ upper limit on the dimensionless strain amplitude $A$ of the background of $A, 24 pages, 5 tables, 17 figures
Published: 2015
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23. European Pulsar Timing Array limits on continuous gravitational waves from individual supermassive slack hole binaries

Author: Alberto Vecchio, S. Sanidas, Jonathan R. Gair, R. van Haasteren, L. Lentati, P. Lazarus, A. Possenti, R. N. Caballero, C. G. Bassa, Antoine Petiteau, S. Babak, Gregory Desvignes, Stephen Taylor, Gilles Theureau, R. Smits, Jason W. T. Hessels, Pablo Rosado, Michael Kramer, A. Lassus, D. J. Champion, Chiara M. F. Mingarelli, Benjamin Stappers, Gemma H. Janssen, Alberto Sesana, M. B. Purver, Lucas Guillemot, P. Brem, M. Burgay, Caterina Tiburzi, Stefan Oslowski, Kejia Lee, Joris P. W. Verbiest, Delphine Perrodin, Ramesh Karuppusamy, Ismaël Cognard, Kang Liu, Babak, S, Petiteau, A, Sesana, A, Brem, P, Rosado, P, Taylor, S, Lassus, A, Hessels, J, Bassa, C, Burgay, M, Caballero, R, Champion, D, Cognard, I, Desvignes, G, Gair, J, Guillemot, L, Janssen, G, Karuppusamy, R, Kramer, M, Lazarus, P, Lee, K, Lentati, L, Liu, K, Mingarelli, C, Oslowski, S, Perrodin, D, Possenti, A, Purver, M, Sanidas, S, Smits, R, Stappers, B, Theureau, G, Tiburzi, C, van Haasteren, R, Vecchio, A, Verbiest, J, Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, APC - Gravitation (APC-Gravitation), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Netherlands Institute for Radio Astronomy (ASTRON), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Radioastronomie (MPIFR), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], Cavendish Laboratory, Netherlands Institute for Radio Astronomy ( ASTRON ), Laboratoire Univers et Théories (LUTH (UMR_8102)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], School of Physics and Astronomy [Birmingham], University of Birmingham [Birmingham], European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), NASA-California Institute of Technology (CALTECH), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Universiteit Leiden, High Energy Astrophys. & Astropart. Phys (API, FNWI), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Institute of Astronomy, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), astro-ph.GA, gr-qc, Population, black hole physics, FOS: Physical sciences, Astrophysics, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, General Relativity and Quantum Cosmology, Pulsar timing array, Black hole physic, Pulsar, 0103 physical sciences, education, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Physics, education.field_of_study, Supermassive black hole, 010308 nuclear & particles physics, Gravitational wave, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, European Pulsar Timing Array, Pulsars: general, Amplitude, gravitational waves, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), astro-ph.CO, Astrophysics - Instrumentation and Methods for Astrophysics, Noise (radio), Astrophysics - Cosmology and Nongalactic Astrophysics, astro-ph.IM
Abstract: We have searched for continuous gravitational wave (CGW) signals produced by individually resolvable, circular supermassive black hole binaries (SMBHBs) in the latest EPTA dataset, which consists of ultra-precise timing data on 41 millisecond pulsars. We develop frequentist and Bayesian detection algorithms to search both for monochromatic and frequency-evolving systems. None of the adopted algorithms show evidence for the presence of such a CGW signal, indicating that the data are best described by pulsar and radiometer noise only. Depending on the adopted detection algorithm, the 95\% upper limit on the sky-averaged strain amplitude lies in the range $6\times 10^{-15}10^9$M$_\odot$ out to a distance of about 25Mpc, and with $\cal{M}_c>10^{10}$M$_\odot$ out to a distance of about 1Gpc ($z\approx0.2$). We show that state-of-the-art SMBHB population models predict $, Comment: 16 pages, 11 figures, accepted for publication in MNRAS
Published: 2015
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24. Radio pulsars: Testing gravity and detecting gravitational waves

Author: Delphine Perrodin, Alberto Sesana, Rezzolla, L, Pizzochero, P, Jones, DI, Rea, N, Vidana, I, Perrodin, D, and Sesana, A
Subjects: Physics, Millisecond, Gravity (chemistry), 010308 nuclear & particles physics, General relativity, Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics, 01 natural sciences, Stability (probability), Atomic clock, Pulsar, Millisecond pulsar, 0103 physical sciences, pulsars, gravitational waves, black holes, general relativity, 010303 astronomy & astrophysics
Abstract: Pulsars are the most stable macroscopic clocks found in nature. Spinning with periods as short as a few milliseconds, their stability can supersede that of the best atomic clocks on Earth over timescales of a few years. Stable clocks are synonymous with precise measurements, which is why pulsars play a role of paramount importance in testing fundamental physics. As a pulsar rotates, the radio beam emitted along its magnetic axis appears to us as pulses because of the lighthouse effect. Thanks to the extreme regularity of the emitted pulses, minuscule disturbances leave particular fingerprints in the times-of-arrival (TOAs) measured on Earth with the technique of pulsar timing. Tiny deviations from the expected TOAs, predicted according to a theoretical timing model based on known physics, can therefore reveal a plethora of interesting new physical effects. Pulsar timing can be used to measure the dynamics of pulsars in compact binaries, thus probing the post-Newtonian expansion of general relativity beyond the weak field regime, while offering unique possibilities of constraining alternative theories of gravity. Additionally, the correlation of TOAs from an ensemble of millisecond pulsars can be exploited to detect low-frequency gravitational waves of astrophysical and cosmological origins. We present a comprehensive review of the many applications of pulsar timing as a probe of gravity, describing in detail the general principles, current applications and results, as well as future prospects.
Published: 2017

25. The Sardinia Radio Telescope . From a technological project to a radio observatory

Author: G. Serra, G. Valente, Elise Egron, M. Buttu, Federica Govoni, Maura Pilia, I. Prandoni, F. T. Nasir, A. Orlati, Alessio Trois, Andrea Tarchi, A. Pellizzoni, Roberto Ricci, C. Stanghellini, Matteo Murgia, S. Casu, Valentina Vacca, Gianni Comoretto, M. N. Iacolina, F. Loi, N. D'Amico, A. Orfei, Delphine Perrodin, Sergio Poppi, Francesco Gaudiomonte, Tonino Pisanu, Paola Castangia, Pietro Bolli, Raimondo Concu, S. Loru, Marco Bartolini, Alessandro Corongiu, Andrea Melis, Caterina Tiburzi, A. Fara, Alessandro Ridolfi, S. Righini, Matteo Bachetti, Ettore Carretti, F. Massi, C. Migoni, M. Burgay, D. Guidetti, A. Zanichelli, Steven Tingay, I. Porceddu, ITA, and AUS
Subjects: European VLBI Network, 010308 nuclear & particles physics, business.industry, Computer science, FOS: Physical sciences, Astronomy and Astrophysics, First light, Active surface, 01 natural sciences, Sextant (astronomical), law.invention, Radio telescope, Telescope, Pulsar, Space and Planetary Science, law, 0103 physical sciences, Instrumentation (computer programming), Telecommunications, business, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics
Abstract: [Abridged] The Sardinia Radio Telescope (SRT) is the new 64-m dish operated by INAF (Italy). Its active surface will allow us to observe at frequencies of up to 116 GHz. At the moment, three receivers, one per focal position, have been installed and tested. The SRT was officially opened in October 2013, upon completion of its technical commissioning phase. In this paper, we provide an overview of the main science drivers for the SRT, describe the main outcomes from the scientific commissioning of the telescope, and discuss a set of observations demonstrating the SRT's scientific capabilities. One of the main objectives of scientific commissioning was the identification of deficiencies in the instrumentation and/or in the telescope sub-systems for further optimization. As a result, the overall telescope performance has been significantly improved. As part of the scientific commissioning activities, different observing modes were tested and validated, and first astronomical observations were carried out to demonstrate the science capabilities of the SRT. In addition, we developed astronomer-oriented software tools, to support future observers on-site. The astronomical validation activities were prioritized based on technical readiness and scientific impact. The highest priority was to make the SRT available for joint observations as part of European networks. As a result, the SRT started to participate (in shared-risk mode) in EVN (European VLBI Network) and LEAP (Large European Array for Pulsars) observing sessions in early 2014. The validation of single-dish operations for the suite of SRT first light receivers and backends continued in the following years, and was concluded with the first call for shared-risk/early-science observations issued at the end of 2015., 26 pages, 18 figures, accepted for publication in Section 13 'Astronomical instrumentation' of Astronomy & Astrophysics
Published: 2017

26. Statistical analyses for NANOGrav 5-year timing residuals

Author: Fredrick A. Jenet, Yan Wang, X. Siemens, James M. Cordes, Dustin R. Madison, Shami Chatterjee, Paul Demorest, Michele Vallisneri, Timothy Dolch, Michael T. Lam, Joanna M. Rankin, Justin A. Ellis, Maura McLaughlin, Delphine Perrodin, ITA, USA, and CHN
Subjects: 010308 nuclear & particles physics, Gravitational wave, FOS: Physical sciences, Astronomy and Astrophysics, White noise, Geodesy, 01 natural sciences, Noise, Pulsar, Space and Planetary Science, Observatory, 0103 physical sciences, Outlier, Arecibo Observatory, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Mathematics, Statistical hypothesis testing
Abstract: In pulsar timing, timing residuals are the differences between the observed times of arrival and the predictions from the timing model. A comprehensive timing model will produce featureless residuals, which are presumably composed of dominating noise and weak physical effects excluded from the timing model (e.g. gravitational waves). In order to apply the optimal statistical methods for detecting the weak gravitational wave signals, we need to know the statistical properties of the noise components in the residuals. In this paper we utilize a variety of non-parametric statistical tests to analyze the whiteness and Gaussianity of the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) 5-year timing data which are obtained from the Arecibo Observatory and the Green Bank Telescope from 2005 to 2010 (Demorest et al. 2013). We find that most of the data are consistent with white noise; Many data deviate from Gaussianity at different levels, nevertheless, removing outliers in some pulsars will mitigate the deviations., Comment: 15 pages, 11 figures, 2 tables. Accepted by RAA
Published: 2017

27. The beamformer and correlator for the Large European Array for Pulsars

Author: Cees Bassa, Ben Stappers, M. B. Purver, James Mckee, R. Smits, Weiwei Zhu, Michael Kramer, Sotirios A. Sanidas, Kejia Lee, Delphine Perrodin, Gemma H. Janssen, Ramesh Karuppusamy, Kuo Liu, Netherlands Institute for Radio Astronomy (ASTRON), Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], Max-Planck-Institut für Radioastronomie (MPIFR), Peking University [Beijing], Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), European Project: 617199,EC:FP7:ERC,ERC-2013-CoG,ALERT(2014), European Project: 610058,EC:FP7:ERC,ERC-2013-SyG,BLACKHOLECAM(2014), European Project: 227947,EC:FP7:ERC,ERC-2008-AdG,LEAP(2009), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), High Energy Astrophys. & Astropart. Phys (API, FNWI), ITA, GBR, FRA, DEU, NLD, and CHN
Subjects: Interferometric, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, 01 natural sciences, law.invention, Gravitational waves, Radio telescope, Telescope, Optics, Software, Pulsar, law, Millisecond pulsar, pulsars: general, 0103 physical sciences, 010306 general physics, General, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Pulsars, Physics, business.industry, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Polarization (waves), Techniques, Computer Science Applications, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Interferometry, gravitational waves, Space and Planetary Science, general, techniques: interferometric, interferometric, business, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Large European Array for Pulsars combines Europe's largest radio telescopes to form a tied-array telescope that provides high signal-to-noise observations of millisecond pulsars (MSPs) with the objective to increase the sensitivity of detecting low-frequency gravitational waves. As part of this endeavor we have developed a software correlator and beamformer which enables the formation of a tied-array beam from the raw voltages from each of telescopes. We explain the concepts and techniques involved in the process of adding the raw voltages coherently. We further present the software processing pipeline that is specifically designed to deal with data from widely spaced, inhomogeneous radio telescopes and describe the steps involved in preparing, correlating and creating the tied-array beam. This includes polarization calibration, bandpass correction, frequency dependent phase correction, interference mitigation and pulsar gating. A link is provided where the software can be obtained., Comment: 10 pages, 6 figures, accepted for publication in Astronomy and Computing
Published: 2017
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28. Imaging of SNR IC443 and W44 with the Sardinia Radio Telescope at 1.5 and 7 GHz

Author: G. P. Vargiu, M. Marongiu, Francesco Gaudiomonte, Tonino Pisanu, Gian Luigi Deiana, F. Loi, Alessandro Navarrini, Delphine Perrodin, E. Urru, D. Simeone, V. Vacca, G. Serra, S. Loru, M. Buttu, Andrea Melis, M. Cardillo, Maura Pilia, A. Ladu, Alessio Trois, Franco Buffa, G. Valente, Raimondo Concu, Matteo Bachetti, A. Pellizzoni, Roberto Ricci, P. Marongiu, S. Mulas, E. Egron, A. Giuliani, Antonietta Fara, Sergio Poppi, G. Murtas, M. N. Iacolina, A. Saba, Simona Righini, Carlo Migoni, and ITA
Subjects: Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Spectral index, Astrophysics::High Energy Astrophysical Phenomena, Flux, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Cosmic ray, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Spectral line, Interstellar medium, Radio telescope, Particle acceleration, Supernova, Space and Planetary Science, 0103 physical sciences, Astrophysics - High Energy Astrophysical Phenomena, 010306 general physics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics
Abstract: Observations of supernova remnants (SNRs) are a powerful tool for investigating the later stages of stellar evolution, the properties of the ambient interstellar medium, and the physics of particle acceleration and shocks. For a fraction of SNRs, multi-wavelength coverage from radio to ultra high-energies has been provided, constraining their contributions to the production of Galactic cosmic rays. Although radio emission is the most common identifier of SNRs and a prime probe for refining models, high-resolution images at frequencies above 5 GHz are surprisingly lacking, even for bright and well-known SNRs such as IC443 and W44. In the frameworks of the Astronomical Validation and Early Science Program with the 64-m single-dish Sardinia Radio Telescope, we provided, for the first time, single-dish deep imaging at 7 GHz of the IC443 and W44 complexes coupled with spatially-resolved spectra in the 1.5-7 GHz frequency range. Our images were obtained through on-the-fly mapping techniques, providing antenna beam oversampling and resulting in accurate continuum flux density measurements. The integrated flux densities associated with IC443 are S_1.5GHz = 134 +/- 4 Jy and S_7GHz = 67 +/- 3 Jy. For W44, we measured total flux densities of S_1.5GHz = 214 +/- 6 Jy and S_7GHz = 94 +/- 4 Jy. Spectral index maps provide evidence of a wide physical parameter scatter among different SNR regions: a flat spectrum is observed from the brightest SNR regions at the shock, while steeper spectral indices (up to 0.7) are observed in fainter cooling regions, disentangling in this way different populations and spectra of radio/gamma-ray-emitting electrons in these SNRs., Comment: 13 pages, 9 figures, accepted for publication to MNRAS on 18 May 2017
Published: 2017

29. A real-time KLT implementation for radio-SETI applications

Author: Francesco Schillirò, Alessandro Bocchinu, Valentina Vacca, Tonino Pisanu, Nicoló Antonietti, Pierpaolo Pari, Matteo Murgia, G. Valente, Alessandro Navarrini, Massimo Barbaro, Stelio Montebugnoli, Raimondo Concu, Maria Ilaria Lunesu, Delphine Perrodin, Claudio Maccone, S. Casu, Andrea Melis, Jader Monari, Alessio Trois, Andrea Possenti, and Carlo Migoni
Subjects: Theoretical computer science, Computer science, Computation, Fast Fourier transform, Scale (descriptive set theory), 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, 010309 optics, Computer engineering, 0103 physical sciences, 0210 nano-technology, Field-programmable gate array, Search for extraterrestrial intelligence
Abstract: SETI, the Search for ExtraTerrestrial Intelligence, is the search for radio signals emitted by alien civilizations living in the Galaxy. Narrow-band FFT-based approaches have been preferred in SETI, since their computation time only grows like N*lnN, where N is the number of time samples. On the contrary, a wide-band approach based on the Kahrunen-Lo`eve Transform (KLT) algorithm would be preferable, but it would scale like N*N. In this paper, we describe a hardware-software infrastructure based on FPGA boards and GPU-based PCs that circumvents this computation-time problem allowing for a real-time KLT.
Published: 2016
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30. A glitch in the millisecond pulsar J0613-0200

Author: Caterina Tiburzi, L. Lentati, G. Shaifullah, James Mckee, Andrew Lyne, Christine Jordan, R. N. Caballero, Ramesh Karuppusamy, Ismaël Cognard, Gemma H. Janssen, E. Graikou, D. J. Champion, Joris P. W. Verbiest, Benjamin Stappers, Stefan Oslowski, Michael Kramer, Delphine Perrodin, Gregory Desvignes, Axel Jessner, P. Lazarus, Jodrell Bank Centre for Astrophysics (JBCA), University of Manchester [Manchester], Jodrell Bank Centre for Astrophysics, Max-Planck-Institut für Radioastronomie (MPIFR), Cavendish Laboratory, University of Cambridge [UK] (CAM), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Columbia Astrophysics Laboratory (CAL), Columbia University [New York], Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Universität Bielefeld, INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Region Centre in France, European Project: 279702,EC:FP7:ERC,ERC-2011-StG_20101014,BEACON(2011), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), ITA, GBR, FRA, DEU, NLD, Mckee, J, Janssen, G, Stappers, B, Lyne, A, Caballero, R, Lentati, L, Desvignes, G, Jessner, A, Jordan, C, Karuppusamy, R, Kramer, M, Cognard, I, Champion, D, Graikou, E, Lazarus, P, Osłowski, S, Perrodin, D, Shaifullah, G, Tiburzi, C, and Verbiest, J
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Pulsar planet, FOS: Physical sciences, Astrophysics, 01 natural sciences, Binary pulsar, law.invention, Telescope, stars: neutron, stars:rotation, Pulsar timing array, pulsars: individual: PSR J0613-0200, Pulsar, stars: rotation, law, Millisecond pulsar, pulsars: general, 0103 physical sciences, stars:neutron, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, 010308 nuclear & particles physics, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, pulsars:general, Astrophysics - Solar and Stellar Astrophysics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Glitch (astronomy), Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, pulsars:individual (PSR J0613 − 0200)
Abstract: We present evidence for a small glitch in the spin evolution of the millisecond pulsar J0613$-$0200, using the EPTA Data Release 1.0, combined with Jodrell Bank analogue filterbank TOAs recorded with the Lovell telescope and Effelsberg Pulsar Observing System TOAs. A spin frequency step of 0.82(3) nHz and frequency derivative step of ${-1.6(39) \times 10^{-19}\,\text{Hz} \ \text{s}^{-1}}$ are measured at the epoch of MJD 50888(30). After PSR B1821$-$24A, this is only the second glitch ever observed in a millisecond pulsar, with a fractional size in frequency of ${\Delta \nu/\nu=2.5(1) \times 10^{-12}}$, which is several times smaller than the previous smallest glitch. PSR J0613$-$0200 is used in gravitational wave searches with pulsar timing arrays, and is to date only the second such pulsar to have experienced a glitch in a combined 886 pulsar-years of observations. We find that accurately modelling the glitch does not impact the timing precision for pulsar timing array applications. We estimate that for the current set of millisecond pulsars included in the International Pulsar Timing Array, there is a probability of $\sim 50$% that another glitch will be observed in a timing array pulsar within 10 years., Comment: accepted for publication in MNRAS
Published: 2016
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31. The noise properties of 42 millisecond pulsars from the European Pulsar Timing Array and their impact on gravitational-wave searches

Author: Chiara M. F. Mingarelli, Benjamin Stappers, Alberto Vecchio, S. Babak, Caterina Tiburzi, R. N. Caballero, Kang Liu, A. Lassus, Stefan Oslowski, C. G. Bassa, Delphine Perrodin, Lucas Guillemot, R. van Haasteren, Kejia Lee, P. Brem, E. Graikou, Jason W. T. Hessels, Joris P. W. Verbiest, Pablo Rosado, M. B. Purver, D. J. Champion, Gemma H. Janssen, Ramesh Karuppusamy, Ismaël Cognard, Jonathan R. Gair, G. Shaifullah, J. W. McKee, Stephen Taylor, Michael Kramer, Antoine Petiteau, R. Smits, Alberto Sesana, P. Lazarus, S. Sanidas, L. Lentati, M. Burgay, A. Possenti, Gregory Desvignes, Gilles Theureau, High Energy Astrophys. & Astropart. Phys (API, FNWI), Caballero, R, Lee, K, Lentati, L, Desvignes, G, Champion, D, Verbiest, J, Janssen, G, Stappers, B, Kramer, M, Lazarus, P, Possenti, A, Tiburzi, C, Perrodin, D, Osłowski, S, Babak, S, Bassa, C, Brem, P, Burgay, M, Cognard, I, Gair, J, Graikou, E, Guillemot, L, Hessels, J, Karuppusamy, R, Lassus, A, Liu, K, Mckee, J, Mingarelli, C, Petiteau, A, Purver, M, Rosado, P, Sanidas, S, Sesana, A, Shaifullah, G, Smits, R, Taylor, S, Theureau, G, van Haasteren, R, Vecchio, A, Max-Planck-Institut für Radioastronomie (MPIFR), Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], Cavendish Laboratory, University of Cambridge [UK] (CAM), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Columbia Astrophysics Laboratory (CAL), Columbia University [New York], Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Universität Bielefeld, Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), School of Mathematics - University of Edinburgh, University of Edinburgh, Netherlands Institute for Radio Astronomy (ASTRON), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), APC - Gravitation (APC-Gravitation), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft-Max-Planck-Gesellschaft, Netherlands Institute for Radio Astronomy ( ASTRON ), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), School of Physics and Astronomy [Birmingham], University of Birmingham [Birmingham], Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), California Institute of Technology (CALTECH)-NASA, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI)
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, 01 natural sciences, Binary pulsar, Pulsar, Millisecond pulsar, pulsars: general, 0103 physical sciences, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, gravitational waves – methods: data analysis – pulsars: general, Physics, Supermassive black hole, 010308 nuclear & particles physics, Gravitational wave, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, methods: data analysis, European Pulsar Timing Array, Amplitude, gravitational waves, 13. Climate action, Space and Planetary Science, Astrophysics - Instrumentation and Methods for Astrophysics, Noise (radio), Astrophysics - Cosmology and Nongalactic Astrophysics, Methods: data analysi
Abstract: The sensitivity of Pulsar Timing Arrays to gravitational waves depends on the noise present in the individual pulsar timing data. Noise may be either intrinsic or extrinsic to the pulsar. Intrinsic sources of noise will include rotational instabilities, for example. Extrinsic sources of noise include contributions from physical processes which are not sufficiently well modelled, for example, dispersion and scattering effects, analysis errors and instrumental instabilities. We present the results from a noise analysis for 42 millisecond pulsars (MSPs) observed with the European Pulsar Timing Array. For characterising the low-frequency, stochastic and achromatic noise component, or "timing noise", we employ two methods, based on Bayesian and frequentist statistics. For 25 MSPs, we achieve statistically significant measurements of their timing noise parameters and find that the two methods give consistent results. For the remaining 17 MSPs, we place upper limits on the timing noise amplitude at the 95% confidence level. We additionally place an upper limit on the contribution to the pulsar noise budget from errors in the reference terrestrial time standards (below 1%), and we find evidence for a noise component which is present only in the data of one of the four used telescopes. Finally, we estimate that the timing noise of individual pulsars reduces the sensitivity of this data set to an isotropic, stochastic GW background by a factor of >9.1 and by a factor of >2.3 for continuous GWs from resolvable, inspiralling supermassive black-hole binaries with circular orbits., Accepted for publication by the Monthly Notices of the Royal Astronomical Society
Published: 2016
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32. A millisecond pulsar in an extremely wide binary system

Author: Benjamin Stappers, R. Smits, Kejia Lee, Lucas Guillemot, E. Graikou, R. N. Caballero, C. G. Bassa, Gemma H. Janssen, P. Lazarus, Joris P. W. Verbiest, Weiwei Zhu, Thomas Wevers, Peter G. Jonker, Ramesh Karuppusamy, S. Sanidas, G. Shaifullah, Ismaël Cognard, Andrew Lyne, A. Jessner, J. W. McKee, Michael Kramer, Caterina Tiburzi, K. Lazaridis, Stefan Oslowski, Paulo C. C. Freire, D. J. Champion, Thomas M. Tauris, Kang Liu, Christine Jordan, Delphine Perrodin, L. Lentati, Gregory Desvignes, Gilles Theureau, Netherlands Institute for Radio Astronomy (ASTRON), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Argelander-Institut für Astronomie (AlfA), Rheinische Friedrich-Wilhelms-Universität Bonn, Max-Planck-Institut für Radioastronomie (MPIFR), Department of Astrophysics [Nijmegen], Institute for Mathematics, Astrophysics and Particle Physics (IMAPP), Radboud university [Nijmegen]-Radboud university [Nijmegen], SRON Netherlands Institute for Space Research (SRON), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Fakultät für Physik, Universität Bielefeld, Universität Bielefeld, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Anton Pannekoek Institute for Astronomy, University of Amsterdam [Amsterdam] (UvA), Laboratoire Univers et Théories (LUTH (UMR_8102)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Programme National de Cosmologie and Galaxies' (PNCG) of CNRS/INSU, France., European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), European Project: 610058,EC:FP7:ERC,ERC-2013-SyG,BLACKHOLECAM(2014), ITA, GBR, FRA, DEU, TWN, NLD, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Bassa, C, Janssen, G, Stappers, B, Tauris, T, Wevers, T, Jonker, P, Lentati, L, Verbiest, J, Desvignes, G, Graikou, E, Guillemot, L, Freire, P, Lazarus, P, Caballero, R, Champion, D, Cognard, I, Jessner, A, Jordan, C, Karuppusamy, R, Kramer, M, Lazaridis, K, Lee, K, Liu, K, Lyne, A, Mckee, J, Osłowski, S, Perrodin, D, Sanidas, S, Shaifullah, G, Smits, R, Theureau, G, Tiburzi, C, Zhu, W, Radboud University [Nijmegen]-Radboud University [Nijmegen], Universität Bielefeld = Bielefeld University, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: stars: individual: PSR J1024-0719, Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Pulsar planet, Supernovae: general, FOS: Physical sciences, Astrophysics, 01 natural sciences, Binary pulsar, stars: neutron, Pulsar, Millisecond pulsar, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], supernovae: general, Astronomy and Astrophysics, European Pulsar Timing Array, Neutron star, binaries: general, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Sub-Earth, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, X-ray pulsar
Abstract: We report on 22 yrs of radio timing observations of the millisecond pulsar J1024$-$0719 by the telescopes participating in the European Pulsar Timing Array (EPTA). These observations reveal a significant second derivative of the pulsar spin frequency and confirm the discrepancy between the parallax and Shklovskii distances that has been reported earlier. We also present optical astrometry, photometry and spectroscopy of 2MASS J10243869$-$0719190. We find that it is a low-metallicity main-sequence star (K7V spectral type, $\mathrm{[M/H]}=-1.0$, $T_\mathrm{eff}=4050\pm50$ K) and that its position, proper motion and distance are consistent with those of PSR J1024$-$0719. We conclude that PSR J1024$-$0719 and 2MASS J10243869$-$0719190 form a common proper motion pair and are gravitationally bound. The gravitational interaction between the main-sequence star and the pulsar accounts for the spin frequency derivatives, which in turn resolves the distance discrepancy. Our observations suggest that the pulsar and main-sequence star are in an extremely wide ($P_\mathrm{b}>200$ yr) orbit. Combining the radial velocity of the companion and proper motion of the pulsar, we find that the binary system has a high spatial velocity of $384\pm45$ km s$^{-1}$ with respect to the local standard of rest and has a Galactic orbit consistent with halo objects. Since the observed main-sequence companion star cannot have recycled the pulsar to millisecond spin periods, an exotic formation scenario is required. We demonstrate that this extremely wide-orbit binary could have evolved from a triple system that underwent an asymmetric supernova explosion, though find that significant fine-tuning during the explosion is required. Finally, we discuss the implications of the long period orbit on the timing stability of PSR J1024$-$0719 in light of its inclusion in pulsar timing arrays., 16 pages, 12 figures, 2 tables, submitted for publication in MNRAS
Published: 2016
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33. The 7-beam S-band cryogenic receiver for the SRT primary focus: project status

Author: Alessandro Navarrini, Caterina Tiburzi, A. Uccheddu, Delphine Perrodin, S. Dessi, P. Marongiu, Andrea Melis, M. Buttu, A. Saba, Valentina Vacca, A. Ladu, Giorgio Montisci, N. Iacolina, E. Egron, Tonino Pisanu, Mauro Pili, G. Valente, and ITA
Subjects: Physics, Radio receiver design, business.industry, Linear polarization, 020208 electrical & electronic engineering, Bandwidth (signal processing), 020206 networking & telecommunications, 02 engineering and technology, Polarization (waves), Low noise, Radio telescope, Optics, Cardinal point, 0202 electrical engineering, electronic engineering, information engineering, S band, business
Abstract: Existing radio receivers have a very low noise temperature. To further increase the observation speed, the new generation of radio receivers use a multi-beam focal plane array (FPA) together with wide bandwidth. In this article, we present the front-end and cryogenic design of the 7-beam FPA double linear polarization receiver for the 64-m primary focus of the Sardinia Radio Telescope. At the end of this article, we show the simulated performances of the front-end receiver and the measurements of the down-conversion section.
Published: 2016

34. Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129

Author: Maura Pilia, A. Pellizzoni, Matteo Murgia, V. Vacca, Ettore Carretti, Alessio Trois, M. Burgay, Delphine Perrodin, A. Bocchinu, A. Poddighe, Sergio Poppi, G. Valente, Paola Castangia, P. Marongiu, Raimondo Concu, Alessandro Corongiu, N. D'Amico, Carlo Migoni, Matteo Bachetti, Tonino Pisanu, Andrea Possenti, E. Egron, F. Loi, S. Casu, A. Ladu, G. P. Vargiu, Andrea Melis, Andrea Tarchi, N. Iacolina, and Federica Govoni
Subjects: Cosmology and Nongalactic Astrophysics (astro-ph.CO), Radio galaxy, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, Telescope, Radio telescope, X-shaped radio galaxy, law, 0103 physical sciences, 010306 general physics, 010303 astronomy & astrophysics, Galaxy cluster, Astrophysics::Galaxy Astrophysics, Physics, Linear polarization, Astronomy, Astronomy and Astrophysics, Polarization (waves), Astrophysics - Astrophysics of Galaxies, Galaxy, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present new observations of the galaxy cluster 3C 129 obtained with the Sardinia Radio Telescope in the frequency range 6000-7200 MHz, with the aim to image the large-angular-scale emission at high-frequency of the radio sources located in this cluster of galaxies. The data were acquired using the recently-commissioned ROACH2-based backend to produce full-Stokes image cubes of an area of 1 deg x 1 deg centered on the radio source 3C 129. We modeled and deconvolved the telescope beam pattern from the data. We also measured the instrumental polarization beam patterns to correct the polarization images for off-axis instrumental polarization. Total intensity images at an angular resolution of 2.9 arcmin were obtained for the tailed radio galaxy 3C 129 and for 13 more sources in the field, including 3C 129.1 at the galaxy cluster center. These data were used, in combination with literature data at lower frequencies, to derive the variation of the synchrotron spectrum of 3C 129 along the tail of the radio source. If the magnetic field is at the equipartition value, we showed that the lifetimes of radiating electrons result in a radiative age for 3C 129 of t_syn = 267 +/- 26 Myrs. Assuming a linear projected length of 488 kpc for the tail, we deduced that 3C 129 is moving supersonically with a Mach number of M=v_gal/c_s=1.47. Linearly polarized emission was clearly detected for both 3C 129 and 3C 129.1. The linear polarization measured for 3C 129 reaches levels as high as 70% in the faintest region of the source where the magnetic field is aligned with the direction of the tail., Comment: 19 pages, 17 figures, accepted for publication in MNRAS
Published: 2016
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35. LEAP : The Large European Array for Pulsars

Author: R. Smits, Kejia Lee, Kang Liu, S. Sanidas, M. B. Purver, Ramesh Karuppusamy, Michael Kramer, Gemma H. Janssen, Delphine Perrodin, Benjamin Stappers, J. W. McKee, C. G. Bassa, ITA, GBR, FRA, DEU, TWN, NLD, Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Netherlands Institute for Radio Astronomy ( ASTRON ), Max-Planck-Institut für Radioastronomie (MPIFR), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Jodrell Bank Centre for Astrophysics (JBCA), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Astronomical Institute Anton Pannekoek (AI PANNEKOEK), University of Amsterdam [Amsterdam] (UvA), National Basic Research Program of China, 973 Program, 2015CB857101 and NSFC 11373011, European Project: 227947,EC:FP7:ERC,ERC-2008-AdG,LEAP(2009), High Energy Astrophys. & Astropart. Phys (API, FNWI), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, law.invention, Radio telescope, Telescope, Pulsar, law, 0103 physical sciences, ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Gravitational wave, Antenna aperture, Bandwidth (signal processing), Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], European Pulsar Timing Array, Space and Planetary Science, Astrophysics - Instrumentation and Methods for Astrophysics, data analysis, techniques: interferometric, pulsars: general [gravitational waves, methods], Radio wave
Abstract: The Large European Array for Pulsars (LEAP) is an experiment that harvests the collective power of Europe's largest radio telescopes in order to increase the sensitivity of high-precision pulsar timing. As part of the ongoing effort of the European Pulsar Timing Array (EPTA), LEAP aims to go beyond the sensitivity threshold needed to deliver the first direct detection of gravitational waves. The five telescopes presently included in LEAP are: the Effelsberg telescope, the Lovell telescope at Jodrell Bank, the Nan\c cay radio telescope, the Sardinia Radio Telescope and the Westerbork Synthesis Radio Telescope. Dual polarization, Nyquist-sampled time-series of the incoming radio waves are recorded and processed offline to form the coherent sum, resulting in a tied-array telescope with an effective aperture equivalent to a 195-m diameter circular dish. All observations are performed using a bandwidth of 128 MHz centered at a frequency of 1396 MHz. In this paper, we present the design of the LEAP experiment, the instrumentation, the storage and transfer of data, and the processing hardware and software. In particular, we present the software pipeline that was designed to process the Nyquist-sampled time-series, measure the phase and time delays between each individual telescope and a reference telescope and apply these delays to form the tied-array coherent addition. The pipeline includes polarization calibration and interference mitigation. We also present the first results from LEAP and demonstrate the resulting increase in sensitivity, which leads to an improvement in the pulse arrival times., 15 pages, 12 figures, accepted for publication in MNRAS
Published: 2016
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36. 21 year timing of the black-widow pulsar J2051-0827

Author: Caterina Tiburzi, E. Graikou, Gemma H. Janssen, Norbert Wex, A. Possenti, Christine Jordan, Ben Stappers, Andrew Lyne, R. N. Caballero, Stefan Oslowski, Lucas Guillemot, Michael Kramer, Gregory Desvignes, K. Lazaridis, C. G. Bassa, Axel Jessner, G. Shaifullah, D. J. Champion, P. Lazarus, J. W. McKee, Ramesh Karuppusamy, Ismaël Cognard, Joris P. W. Verbiest, Delphine Perrodin, Thomas M. Tauris, Paulo C. C. Freire, Shaifullah, G, Verbiest, J, Freire, P, Tauris, T, Wex, N, Osłowski, S, Stappers, B, Bassa, C, Caballero, R, Champion, D, Cognard, I, Desvignes, G, Graikou, E, Guillemot, L, Janssen, G, Jessner, A, Jordan, C, Karuppusamy, R, Kramer, M, Lazaridis, K, Lazarus, P, Lyne, A, Mckee, J, Perrodin, D, Possenti, A, Tiburzi, C, Max-Planck-Institut für Radioastronomie (MPIFR), Universität Bielefeld, Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Columbia Astrophysics Laboratory (CAL), Columbia University [New York], Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), and Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Proper motion, general pulsars individual, individual: PSR J2051-0827, Pulsar planet, Binaries: eclipsing, FOS: Physical sciences, fundamental properties pulsars, Astrophysics, 01 natural sciences, Binary pulsar, Radio telescope, Pulsars: individual: PSR J2051-0827, Pulsar, Millisecond pulsar, Binaries: close, 0103 physical sciences, pulsars, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, binaries:close stars, PSR J2051−0827, European Pulsar Timing Array, Pulsars: general, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), binaries:eclipsing, Astrophysics - High Energy Astrophysical Phenomena, X-ray pulsar
Abstract: Timing results for the black-widow pulsar J2051-0827 are presented, using a 21-year dataset from four European Pulsar Timing Array telescopes and the Parkes radio telescope. This dataset, which is the longest published to date for a black-widow system, allows for an improved analysis that addresses previously unknown biases. While secular variations, as identified in previous analyses, are recovered, short-term variations are detected for the first time. Concurrently, a significant decrease of approx. 2.5x10-3 cm-3 pc in the dispersion measure associated with PSR J2051-0827 is measured for the first time and improvements are also made to estimates of the proper motion. Finally, PSR J2051-0827 is shown to have entered a relatively stable state suggesting the possibility of its eventual inclusion in pulsar timing arrays., Accepted for publication by MNRAS, 10 pages, 6 figures
Published: 2016
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37. Variability, polarimetry, and timing properties of single pulses from PSR J1713+0747 using the large European array for pulsars

Author: Kang Liu, Gemma H. Janssen, Michael Kramer, M. B. Purver, R. Smits, Patrick Weltevrede, Kejia Lee, Weiwei Zhu, Ramesh Karuppusamy, James Mckee, S. Sanidas, Cornelis Bassa, Delphine Perrodin, Benjamin Stappers, ITA, GBR, FRA, DEU, TWN, NLD, Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Max-Planck-Institut für Radioastronomie (MPIFR), Netherlands Institute for Radio Astronomy (ASTRON), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Kavli Institute for Astronomy and Astrophysics [Beijing] (KIAA-PKU), Peking University [Beijing], INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), Polarimetry, Flux, FOS: Physical sciences, 01 natural sciences, Optics, Pulsar, 0103 physical sciences, 010303 astronomy & astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), 010308 nuclear & particles physics, Linear polarization, business.industry, Orthogonal polarization spectral imaging, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Pulse (physics), Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), business, Astrophysics - High Energy Astrophysical Phenomena, data analysis, pulsars: individual: PSR J1713+0747 [methods], Bandwidth-limited pulse
Abstract: Single pulses preserve information about the pulsar radio emission and propagation in the pulsar magnetosphere, and understanding the behaviour of their variability is essential for estimating the fundamental limit on the achievable pulsar timing precision. Here we report the findings of our analysis of single pulses from PSR J1713+0747 with data collected by the Large European Array for Pulsars (LEAP). We present statistical studies of the pulse properties that include distributions of their energy, phase and width. Two modes of systematic sub-pulse drifting have been detected, with a periodicity of 7 and 3 pulse periods. The two modes appear at different ranges of pulse longitude but overlap under the main peak of the integrated profile. No evidence for pulse micro-structure is seen with a time resolution down to 140 ns. In addition, we show that the fractional polarisation of single pulses increases with their pulse peak flux density. By mapping the probability density of linear polarisation position angle with pulse longitude, we reveal the existence of two orthogonal polarisation modes. Finally, we find that the resulting phase jitter of integrated profiles caused by single pulse variability can be described by a Gaussian probability distribution only when at least 100 pulses are used for integration. Pulses of different flux densities and widths contribute approximately equally to the phase jitter, and no improvement on timing precision is achieved by using a sub-set of pulses with a specific range of flux density or width., 11 pages, 14 figures, 2 tables, accepted for publication in MNRAS
Published: 2016
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38. Pulsar science at the Sardinia Radio Telescope

Author: M. N. Iacolina, M. Burgay, A. Possenti, Delphine Perrodin, A. Trois, Alessandro Corongiu, Caterina Tiburzi, E. Egron, Raimondo Concu, M. Pilia, A. Pellizzoni, S. Casu, Alessandro Ridolfi, Andrea Melis, ITA, and DEU
Subjects: Radio telescope, Physics, Pulsar, Space and Planetary Science, Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics
Abstract: The Sardinia Radio Telescope (SRT) is a modern, fully-steerable 64-m dish located in San Basilio, Sardinia (Italy). It is characterized by an active surface that allows it to cover a wide range of radio frequencies (300 MHz to 100 GHz). During SRT’s commissioning phase, we installed the hardware and software needed for pulsar observations. Since then, SRT has taken part in Large European Array for Pulsars and European Pulsar Timing Array observations for the purpose of gravitational wave detection. We have installed a new S-band receiver that will allow us to search for pulsars in the Galactic Center. We also plan to combine our efforts to search for Extraterrestrial Intelligence (SETI) with the search for pulsars and Fast Radio Bursts.
Published: 2017
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39. The Scaling of the RMS with Dwell Time in NANOGrav Pulsars

Author: Handzo, Emma, Christy, B., Lommen, Andrea N., and Delphine Perrodin
Subjects: Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract: Pulsar Timing Arrays (PTAs) are collections of well-timed millisecond pulsars that are being used as detectors of gravitational waves (GWs). Given current sensitivity, projected improvements in PTAs and the predicted strength of the GW signals, the detection of GWs with PTAs could occur within the next decade. One way we can improve a PTA is to reduce the measurement noise present in the pulsar timing residuals. If the pulsars included in the array display uncorrelated noise, the root mean square (RMS) of the timing residuals is predicted to scale as $\mathrm{T}^{-1/2}$, where T is the dwell time per observation. In this case, the sensitivity of the array can be increased by increasing T. We studied the 17 pulsars in the five year North American Nanohertz Observatory for Gravitational Waves (NANOGrav) data set to determine if the noise in the timing residuals of the pulsars observed was consistent with this property. For comparison, we performed the same analysis on PSR B1937+21, a pulsar that is known to display red noise. With this method, we find that 15 of the 17 NANOGrav pulsars have timing residuals consistent with the inverse square law. The data also suggest that these 15 pulsars can be observed for up to eight times as long while still exhibiting an RMS that scales as root T., 18 pages, 6 figures
Published: 2015

40. Limits on anisotropy in the nanohertz stochastic gravitational-wave background

Author: Kang Liu, Chiara M. F. Mingarelli, P. Lazarus, R. van Haasteren, R. N. Caballero, Joris P. W. Verbiest, Stefan Oslowski, C. G. Bassa, S. Babak, A. Lassus, Gregory Desvignes, Gilles Theureau, J. R. Gair, Alberto Vecchio, Delphine Perrodin, S. Sanidas, R. Smits, M. Burgay, Caterina Tiburzi, Gemma H. Janssen, L. Lentati, Alberto Sesana, Pablo Rosado, Ramesh Karuppusamy, A. Possenti, Ismaël Cognard, Jason W. T. Hessels, Antoine Petiteau, Stephen Taylor, D. J. Champion, Lucas Guillemot, P. Brem, Ben Stappers, Michael Kramer, M. B. Purver, University of Cambridge [UK] (CAM), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Cavendish Laboratory, Birmingham City University (BCU), Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Radioastronomie (MPIFR), Netherlands Institute for Radio Astronomy (ASTRON), University of Amsterdam [Amsterdam] (UvA), Columbia Astrophysics Laboratory (CAL), Columbia University [New York], Centre de Physique des Particules de Marseille (CPPM), Aix Marseille Université (AMU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Technische Fakultät, Universität Bielefeld, Universität Bielefeld = Bielefeld University, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Centre for Astrophysics and Supercomputing (Centre for Astrophysics and Supercomputing), Swinburne University of Technology [Melbourne], Max Planck Institute for Gravitational Physics (Albert Einstein Institute) (AEI), Programme National de Cosmologie and Galaxies' (PNCG) of CNRS/INSU, France, European Project: 610058,EC:FP7:ERC,ERC-2013-SyG,BLACKHOLECAM(2014), European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), High Energy Astrophys. & Astropart. Phys (API, FNWI), API (FNWI), Taylor, S, Mingarelli, C, Gair, J, Sesana, A, Theureau, G, Babak, S, Bassa, C, Brem, P, Burgay, M, Caballero, R, Champion, D, Cognard, I, Desvignes, G, Guillemot, L, Hessels, J, Janssen, G, Karuppusamy, R, Kramer, M, Lassus, A, Lazarus, P, Lentati, L, Liu, K, Oslowski, S, Perrodin, D, Petiteau, A, Possenti, A, Purver, M, Rosado, P, Sanidas, S, Smits, R, Stappers, B, Tiburzi, C, Van Haasteren, R, Vecchio, A, and Verbiest, J
Subjects: Gravitational wave detectors and experiments, Cosmology and Nongalactic Astrophysics (astro-ph.CO), gr-qc, Population, gravitational waves, pulsar timing, cosmology, General Physics and Astronomy, FOS: Physical sciences, Astrophysics, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, General Relativity and Quantum Cosmology, Gravitational wave background, Pulsar, 0103 physical sciences, education, 010303 astronomy & astrophysics, Pulsars, astro-ph.HE, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), education.field_of_study, Supermassive black hole, Gravitational waves: theory, Galaxy mergers collisions and tidal interactions, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Gravitational wave, European Pulsar Timing Array, Amplitude, astro-ph.CO, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Astrophysics - High Energy Astrophysical Phenomena, Multipole expansion, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: The paucity of observed supermassive black hole binaries (SMBHBs) may imply that the gravitational wave background (GWB) from this population is anisotropic, rendering existing analyses sub-optimal. We present the first constraints on the angular distribution of a nanohertz stochastic GWB from circular, inspiral-driven SMBHBs using the $2015$ European Pulsar Timing Array data [Desvignes et al. (in prep.)]. Our analysis of the GWB in the $\sim 2 - 90$ nHz band shows consistency with isotropy, with the strain amplitude in $l>0$ spherical harmonic multipoles $\lesssim 40\%$ of the monopole value. We expect that these more general techniques will become standard tools to probe the angular distribution of source populations., 6 pages, 2 figures, 1 table. Accepted for publication in Physical Review Letters
Published: 2015
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41. Single-Source Gravitational Wave Limits from the J1713+0747 24-hr Global Campaign

Author: Ramesh Karuppusamy, Ryan Shannon, Ismaël Cognard, Glenn Jones, Timothy Dolch, Duncan R. Lorimer, C. G. Bassa, J. M. Cordes, Kevin Stovall, Paul Demorest, Gemma H. Janssen, T. J. W. Lazio, Jason W. T. Hessels, Fredrick A. Jenet, Christine Jordan, Jayanta Roy, Dustin R. Madison, Joris P. W. Verbiest, P. Lazarus, D. J. Champion, Kathryn Crowter, R. Smits, Nipuni Palliyaguru, Maura McLaughlin, Delphine Perrodin, Bhaswati Bhattacharyya, J. A. Ellis, Daniel R. Stinebring, Michael Kramer, Ingrid H. Stairs, Scott M. Ransom, S. Chatterjee, Michael Keith, Wei Zhu, Michael T. Lam, V. I. Kondratiev, Benjamin Stappers, Department of Physics, Hillsdale College, Jet Propulsion Laboratory ( JPL ), NASA-California Institute of Technology ( CALTECH ), Department of Astronomy [Ithaca], Cornell University, Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Max-Planck-Institut für Radioastronomie ( MPIFR ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Physics and Astronomy [Vancouver], University of British Columbia ( UBC ), National Radio Astronomy Observatory [Socorro] ( NRAO ), National Radio Astronomy Observatory ( NRAO ), Netherlands Institute for Radio Astronomy ( ASTRON ), Center for Gravitational Wave Astronomy, The University of Texas at Brownsville and Texas Southmost College, Columbia Astrophysics Laboratory ( COLUMBIA UNIVERSITY ), Columbia University [New York], Max-Planck-Institut für Radioastronomie, Department of Physics and Astronomy, West Virginia University, West Virginia University [Morgantown], Department of Physics, West Virginia University, West Virginia University, INAF - Osservatorio Astronomico di Cagliari, National Radio Astronomy Observatory [Green Bank] ( NRAO ), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] ( CSIRO ), Department of Physics and Astronomy, University of British Columbia, Physics and Astronomy Department [Oberlin], Oberlin College, Sponsors : int Union Pure & Appl Phys, Korean Astron Soc, Korean Phys Soc, Korean Federat Sci & Technol, Natl Res Fdn, Korea Tourism Organism, Gwangju Convent Bur, ITA, USA, GBR, FRA, DEU, AUS, CAN, IND, NLD, RUS, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Cornell University [New York], Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), University of British Columbia (UBC), National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), Netherlands Institute for Radio Astronomy (ASTRON), Center for Gravitational Wave Astronomy (CGWA), University of Texas Rio Grande Valley [Brownsville, TX] (UTRGV), Columbia Astrophysics Laboratory (CAL), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), National Radio Astronomy Observatory [Green Bank] (NRAO), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Department of Physics and Astronomy [Oberlin], Department of Physics and Astronomy [Albuquerque], and The University of New Mexico [Albuquerque]
Subjects: History, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, BLACK-HOLE BINARIES, 01 natural sciences, Education, Pulsar timing array, Pulsar, Millisecond pulsar, Observatory, 0103 physical sciences, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), [ SDU.ASTR ] Sciences of the Universe [physics]/Astrophysics [astro-ph], astro-ph.HE, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010308 nuclear & particles physics, Gravitational wave, DATA SET, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, PULSAR TIMING ARRAY, Computer Science Applications, European Pulsar Timing Array, Intermediate frequency, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena, Noise (radio), SYSTEM, astro-ph.IM
Abstract: Dense, continuous pulsar timing observations over a 24-hr period provide a method for probing intermediate gravitational wave (GW) frequencies from 10 microhertz to 20 millihertz. The European Pulsar Timing Array (EPTA), the North American Nanohertz Observatory for Gravitational Waves (NANOGrav), the Parkes Pulsar Timing Array (PPTA), and the combined International Pulsar Timing Array (IPTA) all use millisecond pulsar observations to detect or constrain GWs typically at nanohertz frequencies. In the case of the IPTA's nine-telescope 24-Hour Global Campaign on millisecond pulsar J1713+0747, GW limits in the intermediate frequency regime can be produced. The negligible change in dispersion measure during the observation minimizes red noise in the timing residuals, constraining any contributions from GWs due to individual sources. At 10$^{-5}$Hz, the 95% upper limit on strain is 10$^{-11}$ for GW sources in the pulsar's direction., Comment: 4 pages, 2 figures, published in the proceedings of Amaldi 11
Published: 2015
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42. Single-pulse and profile-variability study of PSR J1022+1001

Author: Kejia Lee, Michael Kramer, Benjamin Stappers, Kuo Liu, M. B. Purver, R. Smits, Gemma H. Janssen, Delphine Perrodin, Ramesh Karuppusamy, Unité Scientifique de la Station de Nançay (USN), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Max-Planck-Institut für Radioastronomie (MPIFR), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Netherlands Institute for Radio Astronomy (ASTRON), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), European Project: 227947,EC:FP7:ERC,ERC-2008-AdG,LEAP(2009), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), ITA, GBR, FRA, DEU, and NLD
Subjects: Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, 01 natural sciences, Instability, law.invention, Radio telescope, Telescope, Pulsar, Millisecond pulsar, law, 0103 physical sciences, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Scintillation, 010308 nuclear & particles physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy and Astrophysics, Polarization (waves), Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, Pulse-width modulation
Abstract: Millisecond pulsars (MSPs) are known as highly stable celestial clocks. Nevertheless, recent studies have revealed the unstable nature of their integrated pulse profiles, which may limit the achievable pulsar timing precision. In this paper, we present a case study on the pulse profile variability of PSR J1022+1001. We have detected approximately 14,000 sub-pulses (components of single pulses) in 35-hr long observations, mostly located at the trailing component of the integrated profile. Their flux densities and fractional polarisation suggest that they represent the bright end of the energy distribution in ordinary emission mode and are not giant pulses. The occurrence of sub-pulses from the leading and trailing components of the integrated profile is shown to be correlated. For sub-pulses from the latter, a preferred pulse width of approximately 0.25 ms has been found. Using simultaneous observations from the Effelsberg 100-m telescope and the Westerbork Synthesis Radio Telescope, we have found that the integrated profile varies on a timescale of a few tens of minutes. We show that improper polarisation calibration and diffractive scintillation cannot be the sole reason for the observed instability. In addition, we demonstrate that timing residuals generated from averages of the detected sub-pulses are dominated by phase jitter, and place an upper limit of ~700 ns for jitter noise based on continuous 1-min integrations., 13 pages, 20 figures, 3 tables, accepted for publication in MNRAS
Published: 2015
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43. A multifeed S-band cryogenic receiver for the Sardinia Radio Telescope primary focus

Author: Caterina Tiburzi, A. Ladu, M. Buttu, Alessandro Corongiu, Valentina Vacca, N. Iacolina, Andrea Melis, Giuseppe Mazzarella, P. Marongiu, Francesco Gaudiomonte, Tonino Pisanu, E. Egron, Delphine Perrodin, G. Valente, G. Serra, and Giorgio Montisci
Subjects: Physics, Radio telescope, Time delay and integration, Orthomode transducer, Front and back ends, Noise temperature, Optics, business.industry, Linear polarization, Bandwidth (signal processing), Astrophysics::Instrumentation and Methods for Astrophysics, S band, business
Abstract: The noise temperature of existing radio telescope receivers has actually achieved very low values. In any case, there are other practical ways to increase the observational speed of a single dish antennas without using longer integration time: observe with multi-beam and large bandwidth receiver. In this paper we present the front end and the cryogenic dewar design of the 5 beams FPA double linear polarization receiver for the primary focus of the 64 m Sardinia Radio Telescope.
Published: 2014
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44. Model-based asymptotically optimal dispersion measure correction for pulsar timing

Author: C. G. Bassa, L. Lentati, Ramesh Karuppusamy, Ben Stappers, Khee-Gan Lee, Delphine Perrodin, R. Smits, R. van Haasteren, Gemma H. Janssen, Kang Liu, Michael Kramer, Max-Planck-Institut für Radioastronomie (MPIFR), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Netherlands Institute for Radio Astronomy ( ASTRON ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Cavendish Laboratory, University of Cambridge [UK] (CAM), European Project: 227947,EC:FP7:ERC,ERC-2008-AdG,LEAP(2009), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), and NASA-California Institute of Technology (CALTECH)
Subjects: Physics, 010308 nuclear & particles physics, business.industry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], FOS: Physical sciences, Astronomy and Astrophysics, 01 natural sciences, Measure (mathematics), Pulsar timing array, Noise, Optics, Pulsar, Space and Planetary Science, 0103 physical sciences, Waveform, Statistical dispersion, Sensitivity (control systems), Astrophysics - Instrumentation and Methods for Astrophysics, business, 010303 astronomy & astrophysics, Algorithm, Instrumentation and Methods for Astrophysics (astro-ph.IM), pulsar: general — methods: statistical, Interpolation
Abstract: In order to reach the sensitivity required to detect gravitational waves, pulsar timing array experiments need to mitigate as much noise as possible in timing data. A dominant amount of noise is likely due to variations in the dispersion measure. To correct for such variations, we develop a statistical method inspired by the maximum likelihood estimator and optimal filtering. Our method consists of two major steps. First, the spectral index and amplitude of dispersion measure variations are measured via a time-domain spectral analysis. Second, the linear optimal filter is constructed based on the model parameters found in the first step, and is used to extract the dispersion measure variation waveforms. Compared to current existing methods, this method has better time resolution for the study of short timescale dispersion variations, and generally produces smaller errors in waveform estimations. This method can process irregularly sampled data without any interpolation because of its time-domain nature. Furthermore, it offers the possibility to interpolate or extrapolate the waveform estimation to regions where no data is available. Examples using simulated data sets are included for demonstration., Comment: 15 pages, 15 figures, submitted 15th Sept. 2013, accepted 2nd April 2014 by MNRAS. MNRAS, 2014
Published: 2014
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45. Summary of session C1: pulsar timing arrays

Author: Michael Kramer, Chiara M. F. Mingarelli, S. J. Chamberlin, J.A. Ellis, Kang Liu, Ben Stappers, Khee-Gan Lee, Neil J. Cornish, Linqing Wen, Ryan Shannon, Ramesh Karuppusamy, Alberto Vecchio, Trevor Sidery, Delphine Perrodin, Ilya Mandel, Gemma H. Janssen, Jonathan R. Gair, M. B. Purver, Pablo Rosado, C. G. Bassa, Stephen Taylor, Alberto Sesana, R. Smits, CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Max-Planck-Institut für Radioastronomie (MPIFR), INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Department of Mechanical Engineering, Polytechnic University of Valencia, Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Netherlands Institute for Radio Astronomy (ASTRON), Unité Scientifique de la Station de Nançay (USN), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université d'Orléans (UO), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Physics and Astronomy (miscellaneous), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astrophysics, Signal, Gravitational waves, Pulsar timing array, Pulsar, [SDU]Sciences of the Universe [physics], Session (computer science), Pulsars
Abstract: International audience; This paper summarizes parallel session C1: Pulsar Timing Arrays of the Amaldi10/GR20 Meeting held in Warsaw, Poland in July 2013. The session showcased recent results from pulsar timing array collaborations, advances in modelling the gravitational-wave signal, and new methods to search for and characterize gravitational waves in pulsar timing array observations.
Published: 2014
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46. A 24 HR GLOBAL CAMPAIGN TO ASSESS PRECISION TIMING OF THE MILLISECOND PULSAR J1713+0747

Author: Sourav Chatterjee, Gemma H. Janssen, G. Jones, Fredrick A. Jenet, Christine Jordan, J. W. T. Hessels, I. H. Stairs, Ryan Shannon, T. J. W. Lazio, L. Guillemot, Kang Liu, C. G. Bassa, P. Lazarus, Nipuni Palliyaguru, Michael Kramer, D. R. Madison, E. Petroff, M. A. McLaughlin, J. M. Cordes, Bhaswati Bhattacharyya, Joanna M. Rankin, D. J. Champion, Benjamin Stappers, Kevin Stovall, Michael Keith, Kuan Jin Lee, Joris P. W. Verbiest, Timothy Dolch, Shi Dai, W. W. Zhu, V. I. Kondratiev, A. G. Lyne, Kathryn Crowter, Delphine Perrodin, R. Smits, G. Desvignes, Ramesh Karuppusamy, Benetge Perera, Ismaël Cognard, Paul Demorest, Scott M. Ransom, Jayashree Roy, Michael T. Lam, Oberlin College, Cornell University, Jodrell Bank Centre for Astrophysics, University of Manchester [Manchester], Inter-University Centre for Astronomy and Astrophysics, Max-Planck-Institut für Radioastronomie (MPIFR), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), University of British Colombia, National Radio Astronomy Observatory [Socorro] (NRAO), National Radio Astronomy Observatory (NRAO), Netherlands Institute for Radio Astronomy (ASTRON), University of Amsterdam [Amsterdam] (UvA), Center for Advanced Radio Astronomy (CARA), University of Texas Rio Grande Valley [Brownsville, TX] (UTRGV), ARC Centre of Excellence for Coral Reef Studies (CoralCoE), James Cook University (JCU), CSIRO Astronomy and Space Science, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Vrije Universiteit Medical Centre (VUMC), Vrije Universiteit Amsterdam [Amsterdam] (VU), Max-Planck-Institut für Gravitationsphysik ( Albert-Einstein-Institut ) (AEI), Max-Planck-Gesellschaft, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), School of Medical Sciences - Institute of Medical Sciences, University of Aberdeen, Department of Physics, West Virginia University, West Virginia University, Department of Physics and Astronomy, University of British Columbia, University of British Columbia (UBC), Center for Gravitational Wave Astronomy (CGWA), Department of Physics [Rolla], Missouri University of Science and Technology (Missouri S&T), University of Missouri System-University of Missouri System, INAF - Osservatorio Astronomico di Cagliari (OAC), Istituto Nazionale di Astrofisica (INAF), Laboratory of Infrared Material and Devices, Ningbo University, Centre de Physique des Particules de Marseille (CPPM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Aix Marseille Université (AMU), University of Vermont [Burlington], European Project: 337062,EC:FP7:ERC,ERC-2013-StG,DRAGNET(2014), European Project: 227947,EC:FP7:ERC,ERC-2008-AdG,LEAP(2009), Cornell University [New York], Inter-University Centre for Astronomy and Astrophysics [Pune] (IUCAA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Jodrell Bank Centre for Astrophysics (JBCA), Ningbo University (NBU), Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), and High Energy Astrophys. & Astropart. Phys (API, FNWI)
Subjects: media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, ISM: structure, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Radio telescope, Pulsar, Millisecond pulsar, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, media_common, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Scintillation, Gravitational wave, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, LOFAR, gravitational waves, Space and Planetary Science, Sky, [SDU]Sciences of the Universe [physics], pulsars: individual: PSR J1713+0747, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics, Noise (radio)
Abstract: The radio millisecond pulsar J1713+0747 is regarded as one of the highest-precision clocks in the sky, and is regularly timed for the purpose of detecting gravitational waves. The International Pulsar Timing Array collaboration undertook a 24-hour global observation of PSR J1713+0747 in an effort to better quantify sources of timing noise in this pulsar, particularly on intermediate (1 - 24 hr) timescales. We observed the pulsar continuously over 24 hr with the Arecibo, Effelsberg, GMRT, Green Bank, LOFAR, Lovell, Nancay, Parkes, and WSRT radio telescopes. The combined pulse times-of-arrival presented here provide an estimate of what sources of timing noise, excluding DM variations, would be present as compared to an idealized root-N improvement in timing precision, where N is the number of pulses analyzed. In the case of this particular pulsar, we find that intrinsic pulse phase jitter dominates arrival time precision when the S/N of single pulses exceeds unity, as measured using the eight telescopes that observed at L-band/1.4 GHz. We present first results of specific phenomena probed on the unusually long timescale (for a single continuous observing session) of tens of hours, in particular interstellar scintillation, and discuss the degree to which scintillation and profile evolution affect precision timing. This paper presents the data set as a basis for future, deeper studies., Published in the Astrophysical Journal
Published: 2014
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47. Limits on the Stochastic Gravitational Wave Background from the North American Nanohertz Observatory for Gravitational Waves

Author: Zaven Arzoumanian, Andrea N. Lommen, Joseph K. Swiggum, Paul Demorest, Scott M. Ransom, S. Giampanis, S. J. Chamberlin, David J. Nice, V. M. Kaspi, Sarah Burke-Spolaor, A. Brazier, Fredrick A. Jenet, Joseph Lazio, J. M. Cordes, Nipuni Palliyaguru, Ryan Shannon, Paulo C. C. Freire, Ingrid H. Stairs, X. Siemens, Marjorie Gonzalez, Robert D. Ferdman, Justin A. Ellis, Lee Samuel Finn, Maura McLaughlin, Daniel R. Stinebring, Delphine Perrodin, and Weiwei Zhu
Subjects: Physics, Supermassive black hole, Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010308 nuclear & particles physics, Gravitational wave, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Pulse (physics), Radio telescope, Gravitational wave background, Pulsar, Space and Planetary Science, Observatory, 0103 physical sciences, Astrophysics - Instrumentation and Methods for Astrophysics, Dispersion (water waves), 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract: We present an analysis of high-precision pulsar timing data taken as part of the North American Nanohertz Observatory for Gravitational waves (NANOGrav) project. We have observed 17 pulsars for a span of roughly five years using the Green Bank and Arecibo radio telescopes. We analyze these data using standard pulsar timing models, with the addition of time-variable dispersion measure and frequency-variable pulse shape terms. Sub-microsecond timing residuals are obtained in nearly all cases, and the best root-mean-square timing residuals in this set are ~30-50 ns. We present methods for analyzing post-fit timing residuals for the presence of a gravitational wave signal with a specified spectral shape. These optimally take into account the timing fluctuation power removed by the model fit, and can be applied to either data from a single pulsar, or to a set of pulsars to detect a correlated signal. We apply these methods to our dataset to set an upper limit on the strength of the nHz-frequency stochastic supermassive black hole gravitational wave background of h_c (1 yr^-1) < 7x10^-15 (95%). This result is dominated by the timing of the two best pulsars in the set, PSRs J1713+0747 and J1909-3744., To be submitted to ApJ
Published: 2012
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48. Publisher’s Note: Kerr Black Holes Are Not Unique to General Relativity [Phys. Rev. Lett.100, 091101 (2008)]

Author: Dimitrios Psaltis, Irina Mocioiu, Delphine Perrodin, and Keith R. Dienes
Subjects: Physics, 010308 nuclear & particles physics, General relativity, General Physics and Astronomy, Fuzzball, 01 natural sciences, Black hole, Numerical relativity, Micro black hole, Rotating black hole, Quantum mechanics, 0103 physical sciences, Black brane, 010303 astronomy & astrophysics, Hawking radiation
Published: 2008
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49. Discovery of a new Transient X-ray Pulsar in the Small Magellanic Cloud

Author: Robin H. D. Corbet, Silas Laycock, Delphine Perrodin, M. J. Coe, Frank Marshall, and Craig B. Markwardt
Subjects: Physics, education.field_of_study, Astrophysics::High Energy Astrophysical Phenomena, Population, Astrophysics (astro-ph), Proportional counter, Flux, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Luminosity, Neutron star, Pulsar, Space and Planetary Science, Astrophysics::Solar and Stellar Astrophysics, Small Magellanic Cloud, education, X-ray pulsar
Abstract: Rossi X-Ray Timing Explorer observations of the Small Magellanic Cloud have revealed a previously unknown transient X-ray pulsar with a pulse period of 95s. Provisionally designated XTE SMC95, the pulsar was detected in three Proportional Counter Array observations during an outburst spanning 4 weeks in March/April 1999. The pulse profile is double peaked reaching a pulse fraction \~0.8. The source is proposed as a Be/neutron star system on the basis of its pulsations, transient nature and characteristically hard X-ray spectrum. The 2-10 keV X-ray luminosity implied by our observations is > 2x10^37 erg/s which is consistent with that of normal outbursts seen in Galactic systems. This discovery adds to the emerging picture of the SMC as containing an extremely dense population of transient high mass X-ray binaries., Accepted by A&A. 7 pages, 6 figures
Published: 2002
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50. Discovery of two transient X-ray pulsars in the small magellanic cloud

Author: M. J. Coe, Silas Laycock, C. B. Markwardt, Delphine Perrodin, Robin H. D. Corbet, and F. E. Marshall
Subjects: Physics, education.field_of_study, Astrophysics::High Energy Astrophysical Phenomena, Population, X-ray binary, Astronomy, White dwarf, Astrophysics, Astronomical spectroscopy, Neutron star, Pulsar, Astrophysics::Solar and Stellar Astrophysics, Transient (oscillation), Small Magellanic Cloud, education, Astrophysics::Galaxy Astrophysics
Abstract: Recent RXTE observations of the SMC have revealed two previously unknown transient X-ray pulsars with pulse periods of 95s and 4.78s. The sources are proposed as Be/neutron star systems on the basis of their pulsations, transient nature and characteristically hard spectra. Optical observations indicate an Hα emission-line star as a candidate optical counterpart. These results add to the emerging picture of the SMC as containing an extremely dense population of transient HMXBs, only a fraction of which are active at any one time.
Published: 2001
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