Author: "Mckee, J" - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"Mckee, J"' showing total 1,590 results

Start Over Author "Mckee, J"

1,590 results on '"Mckee, J"'

1. Modeling non stationary noise in pulsar timing array data analysis

Author: Falxa, Mikel, Antoniadis, J., Champion, D. J., Cognard, I., Desvignes, G., Guillemot, L., Hu, H., Janssen, G., Jawor, J., Karuppusamy, R., Keith, M. J., Kramer, M., Lackeos, K., Liu, K., McKee, J. W., Perrodin, D., Sanidas, S. A., Shaifullah, G. M., and Theureau, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract: Pulsar Timing Array (PTA) collaborations recently reported evidence for the presence of a gravitational wave background (GWB) in their datasets. The main candidate that is expected to produce such a GWB is the population of supermassive black hole binaries (SMBHB). Some analyses showed that the recovered signal may exhibit time-dependent properties, i.e. non-stationarity. In this paper, we propose an approximated non-stationary Gaussian process (GP) model obtained from the perturbation of stationary processes. The presented method is applied to the second data release of the European pulsar timing array to search for non-stationary features in the GWB. We analyzed the data in different time slices and showed that the inferred properties of the GWB evolve with time. We find no evidence for such non-stationary behavior and the Bayes factor in favor of the latter is $\mathcal{B}^{NS}_{S} = 1.5$. We argue that the evolution of the GWB properties most likely comes from the \mf{improvement of the observation cadence} with time and \mf{better} characterization of the noise of individual pulsars. Such non-stationary GWB could also be produced by the leakage of non-stationary features in the noise of individual pulsars or by the presence of an eccentric single source., Comment: 14 pages, 14 figures
Published: 2024

2. The Green Bank North Celestial Cap Survey IX: Timing Follow-up for 128 Pulsars

Author: McEwen, A. E., Swiggum, J. K., Kaplan, D. L., Tan, C. M., Meyers, B. W., Fonseca, E., Agazie, G. Y., Chawla, P., Crowter, K., DeCesar, M. E., Dolch, T., Dong, F. A., Fiore, W., Good, D. C., Istrate, A. G., Kaspi, V. M., Kondratiev, V. I., van Leeuwen, J., Levin, L., Lewis, E. F., Lynch, R. S., Masui, K. W., McKee, J. W., McLaughlin, M. A., Noori, H. Al, Parent, E., Ransom, S. M., Siemens, X., Spiewak, R., and Stairs, I. H.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The Green Bank North Celestial Cap survey is one of the largest and most sensitive searches for pulsars and transient radio objects. Observations for the survey have finished; priorities have shifted toward long-term monitoring of its discoveries. In this study, we have developed a pipeline to handle large datasets of archival observations and connect them to recent, high-cadence observations taken using the Canadian Hydrogen Intensity Mapping Experiment (CHIME) telescope. This pipeline handles data for 128 pulsars and has produced measurements of spin, positional, and orbital parameters that connect data over observation gaps as large as 2000 days. We have also measured glitches in the timing residuals for five of the pulsars included and proper motion for 19 sources (13 new). We include updates to orbital parameters for 19 pulsars, including 9 previously unpublished binaries. For two of these binaries, we provide updated measurements of post-Keplerian binary parameters, which result in much more precise estimates of the total masses of both systems. For PSR J0509+3801, the much improved measurement of the Einstein delay yields much improved mass measurements for the pulsar and its companion, 1.399(6)\Msun and 1.412(6)\Msun, respectively. For this system, we have also obtained a measurement of the orbital decay due to the emission of gravitational waves: $\dot{P}_{\rm B} = -1.37(7)\times10^{-12}$, which is in agreement with the rate predicted by general relativity for these masses., Comment: accepted for publication in The Astrophysical Journal
Published: 2023
Full Text: View/download PDF

3. The black widow pulsar J1641+8049 in the optical, radio and X-rays

Author: Kirichenko, A. Yu., Zharikov, S. V., Karpova, A. V., Fonseca, E., Zyuzin, D. A., Shibanov, Yu. A., López, E. A., Gilfanov, M. R., Cabrera-Lavers, A., Geier, S., Dong, F. A., Good, D. C., McKee, J. W., Meyers, B. W., Stairs, I. H., McLaughlin, M. A., and Swiggum, J. K.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract: PSR J1641+8049 is a 2 ms black widow pulsar with the 2.2 h orbital period detected in the radio and $\gamma$-rays. We performed new phase-resolved multi-band photometry of PSR J1641+8049 using the OSIRIS instrument at the Gran Telescopio Canarias. The obtained data were analysed together with the new radio-timing observations from the Canadian Hydrogen Intensity Mapping Experiment (CHIME), the X-ray data from the Spectrum-RG/eROSITA all-sky survey, and all available optical photometric observations. An updated timing solution based on CHIME data is presented, which accounts for secular and periodic modulations in pulse dispersion. The system parameters obtained through the light curve analysis, including the distance to the source 4.6-4.8 kpc and the orbital inclination 56-59 deg, are found to be consistent with previous studies. However, the optical flux of the source at the maximum brightness phase faded by a factor of $\sim$2 as compared to previous observations. Nevertheless, the face of the J1641+8049 companion remains one of the most heated (8000-9500 K) by a pulsar among the known black widow pulsars. We also report a new estimation on the pulsar proper motion of $\approx$2 mas yr$^{-1}$, which yields a spin down luminosity of $\approx$4.87$\times 10^{34}$ ergs s$^{-1}$ and a corresponding heating efficiency of the companion by the pulsar of 0.3-0.7. The pulsar was not detected in X-rays implying its X-ray-luminosity was <3 $\times$ 10$^{31}$ erg s$^{-1}$ at the date of observations., Comment: Accepted for publication in MNRAS
Published: 2023
Full Text: View/download PDF

4. Pulsar Scintillation through Thick and Thin: Bow Shocks, Bubbles, and the Broader Interstellar Medium

Author: Ocker, S. K., Cordes, J. M., Chatterjee, S., Stinebring, D. R., Dolch, T., Pelgrims, V., McKee, J. W., Giannakopoulos, C., and Reardon, D. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: Observations of pulsar scintillation are among the few astrophysical probes of very small-scale ($\lesssim$ au) phenomena in the interstellar medium (ISM). In particular, characterization of scintillation arcs, including their curvature and intensity distributions, can be related to interstellar turbulence and potentially over-pressurized plasma in local ISM inhomogeneities, such as supernova remnants, HII regions, and bow shocks. Here we present a survey of eight pulsars conducted at the Five-hundred-meter Aperture Spherical Telescope (FAST), revealing a diverse range of scintillation arc characteristics at high sensitivity. These observations reveal more arcs than measured previously for our sample. At least nine arcs are observed toward B1929$+$10 at screen distances spanning $\sim 90\%$ of the pulsar's $361$ pc path-length to the observer. Four arcs are observed toward B0355$+$54, with one arc yielding a screen distance as close as $\sim10^5$ au ($<1$ pc) from either the pulsar or the observer. Several pulsars show highly truncated, low-curvature arcs that may be attributable to scattering near the pulsar. The scattering screen constraints are synthesized with continuum maps of the local ISM and other well-characterized pulsar scintillation arcs, yielding a three-dimensional view of the scattering media in context., Comment: 20 pages, 14 figures. Submitted to MNRAS and comments welcome. Interactive version of Figure 12 available at https://stella-ocker.github.io/scattering_ism3d_ocker2023
Published: 2023

5. Constraining the magnetic field geometry of the millisecond pulsar PSR~J0030+0451 from joint radio, thermal X-ray and $\gamma$-ray emission

Author: Pétri, J., Guillot, S., Guillemot, L., Cognard, I., Theureau, G., Grießmeier, J. -M., Bondonneau, L., González-Caniulef, D., Webb, N., Jankowski, F., Kravtsov, I. P., McKee, J. W., Carozzi, T. D., Cecconi, B., Serylak, M., and Zarka, P.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: With the advent of multi-wavelength electromagnetic observations of neutron stars, spanning many decades in photon energies, from radio wavelengths up to X-rays and $\gamma$-rays, it becomes possible to significantly constrain the geometry and the location of the associated emission regions. In this work, we use results from the modelling of thermal X-ray observations of PSR~J0030+0451 from the NICER mission and phase-aligned radio and $\gamma$-ray pulse profiles to constrain the geometry of an off-centred dipole able to reproduce the light-curves in these respective bands simultaneously. To this aim, we deduce a configuration with a simple dipole off-centred from the location of the centre of the thermal X-ray hot spots and show that the geometry is compatible with independent constraints from radio and $\gamma$-ray pulsations only, leading to a fixed magnetic obliquity of $\alpha \approx 75\deg$ and a line of sight inclination angle of $\zeta \approx 54\deg$. We demonstrate that an off-centred dipole cannot be rejected by accounting for the thermal X-ray pulse profiles. Moreover, the crescent shape of one spot is interpreted as the consequence of a small scale surface dipole on top of the large scale off-centred dipole., Comment: Accepted for publication in A&A
Published: 2023
Full Text: View/download PDF

6. Comparing recent PTA results on the nanohertz stochastic gravitational wave background

Author: The International Pulsar Timing Array Collaboration, Agazie, G., Antoniadis, J., Anumarlapudi, A., Archibald, A. M., Arumugam, P., Arumugam, S., Arzoumanian, Z., Askew, J., Babak, S., Bagchi, M., Bailes, M., Nielsen, A. -S. Bak, Baker, P. T., Bassa, C. G., Bathula, A., Bécsy, B., Berthereau, A., Bhat, N. D. R., Blecha, L., Bonetti, M., Bortolas, E., Brazier, A., Brook, P. R., Burgay, M., Burke-Spolaor, S., Burnette, R., Caballero, R. N., Cameron, A., Case, R., Chalumeau, A., Champion, D. J., Chanlaridis, S., Charisi, M., Chatterjee, S., Chatziioannou, K., Cheeseboro, B. D., Chen, S., Chen, Z. -C., Cognard, I., Cohen, T., Coles, W. A., Cordes, J. M., Cornish, N. J., Crawford, F., Cromartie, H. T., Crowter, K., Curyło, M., Cutler, C. J., Dai, S., Dandapat, S., Deb, D., DeCesar, M. E., DeGan, D., Demorest, P. B., Deng, H., Desai, S., Desvignes, G., Dey, L., Dhanda-Batra, N., Di Marco, V., Dolch, T., Drachler, B., Dwivedi, C., Ellis, J. A., Falxa, M., Feng, Y., Ferdman, R. D., Ferrara, E. C., Fiore, W., Fonseca, E., Franchini, A., Freedman, G. E., Gair, J. R., Garver-Daniels, N., Gentile, P. A., Gersbach, K. A., Glaser, J., Good, D. C., Goncharov, B., Gopakumar, A., Graikou, E., Grießmeier, J. -M., Guillemot, L., Gültekin, K., Guo, Y. J., Gupta, Y., Grunthal, K., Hazboun, J. S., Hisano, S., Hobbs, G. B., Hourihane, S., Hu, H., Iraci, F., Islo, K., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jennings, R. J., Jessner, A., Johnson, A. D., Jones, M. L., Joshi, B. C., Kaiser, A. R., Kaplan, D. L., Kapur, A., Kareem, F., Karuppusamy, R., Keane, E. F., Keith, M. J., Kelley, L. Z., Kerr, M., Key, J. S., Kharbanda, D., Kikunaga, T., Klein, T. C., Kolhe, N., Kramer, M., Krishnakumar, M. A., Kulkarni, A., Laal, N., Lackeos, K., Lam, M. T., Lamb, W. G., Larsen, B. B., Lazio, T. J. W., Lee, K. J., Levin, Y., Lewandowska, N., Littenberg, T. B., Liu, K., Liu, T., Liu, Y., Lommen, A., Lorimer, D. R., Lower, M. E., Luo, J., Luo, R., Lynch, R. S., Lyne, A. G., Ma, C. -P., Maan, Y., Madison, D. R., Main, R. A., Manchester, R. N., Mandow, R., Mattson, M. A., McEwen, A., McKee, J. W., McLaughlin, M. A., McMann, N., Meyers, B. W., Meyers, P. M., Mickaliger, M. B., Miles, M., Mingarelli, C. M. F., Mitridate, A., Natarajan, P., Nathan, R. S., Ng, C., Nice, D. J., Niţu, I. C., Nobleson, K., Ocker, S. K., Olum, K. D., Osłowski, S., Paladi, A. K., Parthasarathy, A., Pennucci, T. T., Perera, B. B. P., Perrodin, D., Petiteau, A., Petrov, P., Pol, N. S., Porayko, N. K., Possenti, A., Prabu, T., Leclere, H. Quelquejay, Radovan, H. A., Rana, P., Ransom, S. M., Ray, P. S., Reardon, D. J., Rogers, A. F., Romano, J. D., Russell, C. J., Samajdar, A., Sanidas, S. A., Sardesai, S. C., Schmiedekamp, A., Schmiedekamp, C., Schmitz, K., Schult, L., Sesana, A., Shaifullah, G., Shannon, R. M., Shapiro-Albert, B. J., Siemens, X., Simon, J., Singha, J., Siwek, M. S., Speri, L., Spiewak, R., Srivastava, A., Stairs, I. H., Stappers, B. W., Stinebring, D. R., Stovall, K., Sun, J. P., Surnis, M., Susarla, S. C., Susobhanan, A., Swiggum, J. K., Takahashi, K., Tarafdar, P., Taylor, J., Taylor, S. R., Theureau, G., Thrane, E., Thyagarajan, N., Tiburzi, C., Toomey, L., Turner, J. E., Unal, C., Vallisneri, M., van der Wateren, E., van Haasteren, R., Vecchio, A., Krishnan, V. Venkatraman, Verbiest, J. P. W., Vigeland, S. J., Wahl, H. M., Wang, S., Wang, Q., Witt, C. A., Wang, J., Wang, L., Wayt, K. E., Wu, Z., Young, O., Zhang, L., Zhang, S., Zhu, X. -J., and Zic, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract: The Australian, Chinese, European, Indian, and North American pulsar timing array (PTA) collaborations recently reported, at varying levels, evidence for the presence of a nanohertz gravitational wave background (GWB). Given that each PTA made different choices in modeling their data, we perform a comparison of the GWB and individual pulsar noise parameters across the results reported from the PTAs that constitute the International Pulsar Timing Array (IPTA). We show that despite making different modeling choices, there is no significant difference in the GWB parameters that are measured by the different PTAs, agreeing within $1\sigma$. The pulsar noise parameters are also consistent between different PTAs for the majority of the pulsars included in these analyses. We bridge the differences in modeling choices by adopting a standardized noise model for all pulsars and PTAs, finding that under this model there is a reduction in the tension in the pulsar noise parameters. As part of this reanalysis, we "extended" each PTA's data set by adding extra pulsars that were not timed by that PTA. Under these extensions, we find better constraints on the GWB amplitude and a higher signal-to-noise ratio for the Hellings and Downs correlations. These extensions serve as a prelude to the benefits offered by a full combination of data across all pulsars in the IPTA, i.e., the IPTA's Data Release 3, which will involve not just adding in additional pulsars, but also including data from all three PTAs where any given pulsar is timed by more than as single PTA., Comment: 21 pages, 9 figures, submitted to ApJ
Published: 2023

7. The second data release from the European Pulsar Timing Array: VI. Challenging the ultralight dark matter paradigm

Author: Smarra, Clemente, Goncharov, Boris, Barausse, Enrico, Antoniadis, J., Babak, S., Nielsen, A. -S. Bak, Bassa, C. G., Berthereau, A., Bonetti, M., Bortolas, E., Brook, P. R., Burgay, M., Caballero, R. N., Chalumeau, A., Champion, D. J., Chanlaridis, S., Chen, S., Cognard, I., Desvignes, G., Falxa, M., Ferdman, R. D., Franchini, A., Gair, J. R., Graikou, E., Grie, J. -M., Guillemot, L., Guo, Y. J., Hu, H., Iraci, F., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jessner, A., Karuppusamy, R., Keane, E. F., Keith, M. J., Kramer, M., Krishnakumar, M. A., Lackeos, K., Lee, K. J., Liu, K., Liu, Y., Lyne, A. G., McKee, J. W., Main, R. A., Mickaliger, M. B., Niţu, I. C., Parthasarathy, A., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Leclere, H. Quelquejay, Samajdar, A., Sanidas, S. A., Sesana, A., Shaifullah, G., Speri, L., Spiewak, R., Stappers, B. W., Susarla, S. C., Theureau, G., Tiburzi, C., van der Wateren, E., Vecchio, A., Krishnan, V. Venkatraman, Wang, J., Wang, L., and Wu, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, General Relativity and Quantum Cosmology, High Energy Physics - Phenomenology
Abstract: Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses $10^{-24.0}~\text{eV} \lesssim m \lesssim 10^{-23.3}~\text{eV}$ cannot constitute $100\%$ of the measured local dark matter density, but can have at most local density $\rho\lesssim 0.3$ GeV/cm$^3$., Comment: 5 pages + acknowledgements + refs, 2 figures. Text and figures match the version published in PRL
Published: 2023
Full Text: View/download PDF

8. The second data release from the European Pulsar Timing Array: IV. Implications for massive black holes, dark matter and the early Universe

Author: Antoniadis, J., Arumugam, P., Arumugam, S., Auclair, P., Babak, S., Bagchi, M., Nielsen, A. -S. Bak, Barausse, E., Bassa, C. G., Bathula, A., Berthereau, A., Bonetti, M., Bortolas, E., Brook, P. R., Burgay, M., Caballero, R. N., Caprini, C., Chalumeau, A., Champion, D. J., Chanlaridis, S., Chen, S., Cognard, I., Crisostomi, M., Dandapat, S., Deb, D., Desai, S., Desvignes, G., Dhanda-Batra, N., Dwivedi, C., Falxa, M., Fastidio, F., Ferdman, R. D., Franchini, A., Gair, J. R., Goncharov, B., Gopakumar, A., Graikou, E., Grießmeier, J. -M., Gualandris, A., Guillemot, L., Guo, Y. J., Gupta, Y., Hisano, S., Hu, H., Iraci, F., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jessner, A., Joshi, B. C., Kareem, F., Karuppusamy, R., Keane, E. F., Keith, M. J., Kharbanda, D., Khizriev, T., Kikunaga, T., Kolhe, N., Kramer, M., Krishnakumar, M. A., Lackeos, K., Lee, K. J., Liu, K., Liu, Y., Lyne, A. G., McKee, J. W., Maan, Y., Main, R. A., Mickaliger, M. B., Middleton, H., Neronov, A., Nitu, I. C., Nobleson, K., Paladi, A. K., Parthasarathy, A., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Prabu, T., Postnov, K., Leclere, H. Quelquejay, Rana, P., Pol, A. Roper, Samajdar, A., Sanidas, S. A., Semikoz, D., Sesana, A., Shaifullah, G., Singha, J., Smarra, C., Speri, L., Spiewak, R., Srivastava, A., Stappers, B. W., Steer, D. A., Surnis, M., Susarla, S. C., Susobhanan, A., Takahashi, K., Tarafdar, P., Theureau, G., Tiburzi, C., Truant, R. J., van der Wateren, E., Valtolina, S., Vecchio, A., Krishnan, V. Venkatraman, Verbiest, J. P. W., Wang, J., Wang, L., and Wu, Z.
Subjects: Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, General Relativity and Quantum Cosmology
Abstract: The European Pulsar Timing Array (EPTA) and Indian Pulsar Timing Array (InPTA) collaborations have measured a low-frequency common signal in the combination of their second and first data releases respectively, with the correlation properties of a gravitational wave background (GWB). Such signal may have its origin in a number of physical processes including a cosmic population of inspiralling supermassive black hole binaries (SMBHBs); inflation, phase transitions, cosmic strings and tensor mode generation by non-linear evolution of scalar perturbations in the early Universe; oscillations of the Galactic potential in the presence of ultra-light dark matter (ULDM). At the current stage of emerging evidence, it is impossible to discriminate among the different origins. Therefore, in this paper, we consider each process separately, and investigate the implications of the signal under the hypothesis that it is generated by that specific process. We find that the signal is consistent with a cosmic population of inspiralling SMBHBs, and its relatively high amplitude can be used to place constraints on binary merger timescales and the SMBH-host galaxy scaling relations. If this origin is confirmed, this is the first direct evidence that SMBHBs merge in nature, adding an important observational piece to the puzzle of structure formation and galaxy evolution. As for early Universe processes, the measurement would place tight constraints on the cosmic string tension and on the level of turbulence developed by first-order phase transitions. Other processes would require non-standard scenarios, such as a blue-tilted inflationary spectrum or an excess in the primordial spectrum of scalar perturbations at large wavenumbers. Finally, a ULDM origin of the detected signal is disfavoured, which leads to direct constraints on the abundance of ULDM in our Galaxy., Comment: 30 pages, 23 figures, replaced to match the version published in Astronomy & Astrophysics, note the change in the numbering order in the series (now paper IV)
Published: 2023

9. The second data release from the European Pulsar Timing Array V. Search for continuous gravitational wave signals

Author: Antoniadis, J., Arumugam, P., Arumugam, S., Babak, S., Bagchi, M., Nielsen, A. S. Bak, Bassa, C. G., Bathula, A., Berthereau, A., Bonetti, M., Bortolas, E., Brook, P. R., Burgay, M., Caballero, R. N., Chalumeau, A., Champion, D. J., Chanlaridis, S., Chen, S., Cognard, I., Dandapat, S., Deb, D., Desai, S., Desvignes, G., Dhanda-Batra, N., Dwivedi, C., Falxa, M., Ferranti, I., Ferdman, R. D., Franchini, A., Gair, J. R., Goncharov, B., Gopakumar, A., Graikou, E., Grießmeier, J. M., Guillemot, L., Guo, Y. J., Gupta, Y., Hisano, S., Hu, H., Iraci, F., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jessner, A., Joshi, B. C., Kareem, F., Karuppusamy, R., Keane, E. F., Keith, M. J., Kharbanda, D., Kikunaga, T., Kolhe, N., Kramer, M., Krishnakumar, M. A., Lackeos, K., Lee, K. J., Liu, K., Liu, Y., Lyne, A. G., McKee, J. W., Maan, Y., Main, R. A., Manzini, S., Mickaliger, M. B., Nitu, I. C., Nobleson, K., Paladi, A. K., Parthasarathy, A., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Prabu, T., Leclere, H. Quelquejay, Rana, P., Samajdar, A., Sanidas, S. A., Sesana, A., Shaifullah, G., Singha, J., Speri, L., Spiewak, R., Srivastava, A., Stappers, B. W., Surnis, M., Susarla, S. C., Susobhanan, A., Takahashi, K., Tarafdar, P., Theureau, G., Tiburzi, C., van der Wateren, E., Vecchio, A., Krishnan, V. Venkatraman, Verbiest, J. P. W., Wang, J., Wang, L., and Wu, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies, General Relativity and Quantum Cosmology
Abstract: We present the results of a search for continuous gravitational wave signals (CGWs) in the second data release (DR2) of the European Pulsar Timing Array (EPTA) collaboration. The most significant candidate event from this search has a gravitational wave frequency of 4-5 nHz. Such a signal could be generated by a supermassive black hole binary (SMBHB) in the local Universe. We present the results of a follow-up analysis of this candidate using both Bayesian and frequentist methods. The Bayesian analysis gives a Bayes factor of 4 in favor of the presence of the CGW over a common uncorrelated noise process, while the frequentist analysis estimates the p-value of the candidate to be 1%, also assuming the presence of common uncorrelated red noise. However, comparing a model that includes both a CGW and a gravitational wave background (GWB) to a GWB only, the Bayes factor in favour of the CGW model is only 0.7. Therefore, we cannot conclusively determine the origin of the observed feature, but we cannot rule it out as a CGW source. We present results of simulations that demonstrate that data containing a weak gravitational wave background can be misinterpreted as data including a CGW and vice versa, providing two plausible explanations of the EPTA DR2 data. Further investigations combining data from all PTA collaborations will be needed to reveal the true origin of this feature., Comment: 13 figures, 15 pages, accepted
Published: 2023
Full Text: View/download PDF

10. The second data release from the European Pulsar Timing Array II. Customised pulsar noise models for spatially correlated gravitational waves

Author: Antoniadis, J., Arumugam, P., Arumugam, S., Babak, S., Bagchi, M., Nielsen, A. S. Bak, Bassa, C. G., Bathula, A., Berthereau, A., Bonetti, M., Bortolas, E., Brook, P. R., Burgay, M., Caballero, R. N., Chalumeau, A., Champion, D. J., Chanlaridis, S., Chen, S., Cognard, I., Dandapat, S., Deb, D., Desai, S., Desvignes, G., Dhanda-Batra, N., Dwivedi, C., Falxa, M., Ferdman, R. D., Franchini, A., Gair, J. R., Goncharov, B., Gopakumar, A., Graikou, E., Grießmeier, J. -M., Guillemot, L., Guo, Y. J., Gupta, Y., Hisano, S., Hu, H., Iraci, F., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jessner, A., Joshi, B. C., Kareem, F., Karuppusamy, R., Keane, E. F., Keith, M. J., Kharbanda, D., Kikunaga, T., Kolhe, N., Kramer, M., Krishnakumar, M. A., Lackeos, K., Lee, K. J., Liu, K., Liu, Y., Lyne, A. G., McKee, J. W., Maan, Y., Main, R. A., Mickaliger, M. B., Niţu, I. C., Nobleson, K., Paladi, A. K., Parthasarathy, A., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Prabu, T., Leclere, H. Quelquejay, Rana, P., Samajdar, A., Sanidas, S. A., Sesana, A., Shaifullah, G., Singha, J., Speri, L., Spiewak, R., Srivastava, A., Stappers, B. W., Surnis, M., Susarla, S. C., Susobhanan, A., Takahashi, K., Tarafdar, P., Theureau, G., Tiburzi, C., van der Wateren, E., Vecchio, A., Krishnan, V. Venkatraman, Verbiest, J. P. W., Wang, J., Wang, L., and Wu, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The nanohertz gravitational wave background (GWB) is expected to be an aggregate signal of an ensemble of gravitational waves emitted predominantly by a large population of coalescing supermassive black hole binaries in the centres of merging galaxies. Pulsar timing arrays, ensembles of extremely stable pulsars, are the most precise experiments capable of detecting this background. However, the subtle imprints that the GWB induces on pulsar timing data are obscured by many sources of noise. These must be carefully characterized to increase the sensitivity to the GWB. In this paper, we present a novel technique to estimate the optimal number of frequency coefficients for modelling achromatic and chromatic noise and perform model selection. We also incorporate a new model to fit for scattering variations in the pulsar timing package temponest and created realistic simulations of the European Pulsar Timing Array (EPTA) datasets that allowed us to test the efficacy of our noise modelling algorithms. We present an in-depth analysis of the noise properties of 25 millisecond pulsars (MSPs) that form the second data release (DR2) of the EPTA and investigate the effect of incorporating low-frequency data from the Indian PTA collaboration. We use enterprise and temponest packages to compare noise models with those reported with the EPTA DR1. We find that, while in some pulsars we can successfully disentangle chromatic from achromatic noise owing to the wider frequency coverage in DR2, in others the noise models evolve in a more complicated way. We also find evidence of long-term scattering variations in PSR J1600$-$3053. Through our simulations, we identify intrinsic biases in our current noise analysis techniques and discuss their effect on GWB searches. The results presented here directly help improve sensitivity to the GWB and are already being used as part of global PTA efforts., Comment: 20 pages, 6 figures, 9 tables
Published: 2023
Full Text: View/download PDF

11. The second data release from the European Pulsar Timing Array I. The dataset and timing analysis

Author: Antoniadis, J., Babak, S., Nielsen, A. -S. Bak, Bassa, C. G., Berthereau, A., Bonetti, M., Bortolas, E., Brook, P. R., Burgay, M., Caballero, R. N., Chalumeau, A., Champion, D. J., Chanlaridis, S., Chen, S., Cognard, I., Desvignes, G., Falxa, M., Ferdman, R. D., Franchini, A., Gair, J. R., Goncharov, B., Graikou, E., Grießmeier, J. -M., Guillemot, L., Guo, Y. J., Hu, H., Iraci, F., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jessner, A., Karuppusamy, R., Keane, E. F., Keith, M. J., Kramer, M., Krishnakumar, M. A., Lackeos, K., Lee, K. J., Liu, K., Liu, Y., Lyne, A. G., McKee, J. W., Main, R. A., Mickaliger, M. B., Nitu, I. C., Parthasarathy, A., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Samajdar, H. Quelquejay Leclere A., Sanidas, S. A., Sesana, A., Shaifullah, G., Speri, L., Spiewak, R., Stappers, B. W., Susarla, S. C., Theureau, G., Tiburzi, C., van der Wateren, E., Vecchio, A., Krishnan, V. Venkatraman, Verbiest, J. P. W., Wang, J., Wang, L., and Wu, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies, Astrophysics - Instrumentation and Methods for Astrophysics, General Relativity and Quantum Cosmology
Abstract: Pulsar timing arrays offer a probe of the low-frequency gravitational wave spectrum (1 - 100 nanohertz), which is intimately connected to a number of markers that can uniquely trace the formation and evolution of the Universe. We present the dataset and the results of the timing analysis from the second data release of the European Pulsar Timing Array (EPTA). The dataset contains high-precision pulsar timing data from 25 millisecond pulsars collected with the five largest radio telescopes in Europe, as well as the Large European Array for Pulsars. The dataset forms the foundation for the search for gravitational waves by the EPTA, presented in associated papers. We describe the dataset and present the results of the frequentist and Bayesian pulsar timing analysis for individual millisecond pulsars that have been observed over the last ~25 years. We discuss the improvements to the individual pulsar parameter estimates, as well as new measurements of the physical properties of these pulsars and their companions. This data release extends the dataset from EPTA Data Release 1 up to the beginning of 2021, with individual pulsar datasets with timespans ranging from 14 to 25 years. These lead to improved constraints on annual parallaxes, secular variation of the orbital period, and Shapiro delay for a number of sources. Based on these results, we derived astrophysical parameters that include distances, transverse velocities, binary pulsar masses, and annual orbital parallaxes., Comment: 29 pages, 9 figures, 13 tables, Astronomy & Astrophysics in press
Published: 2023
Full Text: View/download PDF

12. The second data release from the European Pulsar Timing Array III. Search for gravitational wave signals

Author: Antoniadis, J., Arumugam, P., Arumugam, S., Babak, S., Bagchi, M., Nielsen, A. -S. Bak, Bassa, C. G., Bathula, A., Berthereau, A., Bonetti, M., Bortolas, E., Brook, P. R., Burgay, M., Caballero, R. N., Chalumeau, A., Champion, D. J., Chanlaridis, S., Chen, S., Cognard, I., Dandapat, S., Deb, D., Desai, S., Desvignes, G., Dhanda-Batra, N., Dwivedi, C., Falxa, M., Ferdman, R. D., Franchini, A., Gair, J. R., Goncharov, B., Gopakumar, A., Graikou, E., Grießmeier, J. -M., Guillemot, L., Guo, Y. J., Gupta, Y., Hisano, S., Hu, H., Iraci, F., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jessner, A., Joshi, B. C., Kareem, F., Karuppusamy, R., Keane, E. F., Keith, M. J., Kharbanda, D., Kikunaga, T., Kolhe, N., Kramer, M., Krishnakumar, M. A., Lackeos, K., Lee, K. J., Liu, K., Liu, Y., Lyne, A. G., McKee, J. W., Maan, Y., Main, R. A., Mickaliger, M. B., Nitu, I. C., Nobleson, K., Paladi, A. K., Parthasarathy, A., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Prabu, T., Leclere, H. Quelquejay, Rana, P., Samajdar, A., Sanidas, S. A., Sesana, A., Shaifullah, G., Singha, J., Speri, L., Spiewak, R., Srivastava, A., Stappers, B. W., Surnis, M., Susarla, S. C., Susobhanan, A., Takahashi, K., Tarafdar, P., Theureau, G., Tiburzi, C., van der Wateren, E., Vecchio, A., Krishnan, V. Venkatraman, Verbiest, J. P. W., Wang, J., Wang, L., and Wu, Z.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Cosmology and Nongalactic Astrophysics, Astrophysics - Astrophysics of Galaxies
Abstract: We present the results of the search for an isotropic stochastic gravitational wave background (GWB) at nanohertz frequencies using the second data release of the European Pulsar Timing Array (EPTA) for 25 millisecond pulsars and a combination with the first data release of the Indian Pulsar Timing Array (InPTA). We analysed (i) the full 24.7-year EPTA data set, (ii) its 10.3-year subset based on modern observing systems, (iii) the combination of the full data set with the first data release of the InPTA for ten commonly timed millisecond pulsars, and (iv) the combination of the 10.3-year subset with the InPTA data. These combinations allowed us to probe the contributions of instrumental noise and interstellar propagation effects. With the full data set, we find marginal evidence for a GWB, with a Bayes factor of four and a false alarm probability of $4\%$. With the 10.3-year subset, we report evidence for a GWB, with a Bayes factor of $60$ and a false alarm probability of about $0.1\%$ ($\gtrsim 3\sigma$ significance). The addition of the InPTA data yields results that are broadly consistent with the EPTA-only data sets, with the benefit of better noise modelling. Analyses were performed with different data processing pipelines to test the consistency of the results from independent software packages. The inferred spectrum from the latest EPTA data from new generation observing systems is rather uncertain and in mild tension with the common signal measured in the full data set. However, if the spectral index is fixed at 13/3, the two data sets give a similar amplitude of ($2.5\pm0.7)\times10^{-15}$ at a reference frequency of $1\,{\rm yr}^{-1}$. By continuing our detection efforts as part of the International Pulsar Timing Array (IPTA), we expect to be able to improve the measurement of spatial correlations and better characterise this signal in the coming years., Comment: 21 pages, 14 figures, 4 appendix figures, accepted for publication in A&A
Published: 2023
Full Text: View/download PDF

13. Variable Scintillation Arcs of Millisecond Pulsars observed with the Large European Array for Pulsars

Author: Main, R. A., Antoniadis, J., Chen, S., Cognard, I., Hu, H., Jang, J., Karuppusamy, R., Kramer, M., Liu, K., Liu, Y., Mall, G., McKee, J. W., Mickaliger, M. B., Perrodin, D., Sanidas, S. A., Stappers, B. W., Sprenger, T., Wucknitz, O., Bassa, C. G., Burgay, M., Concu, R., Gaikwad, M., Janssen, G. H., Lee, K. J., Melis, A., Pilia, M., Possenti, A., Wang, L., and Zhu, W. W.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract: We present the first large sample of scintillation arcs in millisecond pulsars, analysing 12 sources observed with the Large European Array for Pulsars (LEAP), and the Effelsberg 100\,m telescope. We estimate the delays from multipath propagation, measuring significant correlated changes in scattering timescales over a 10-year timespan. Many sources show compact concentrations of power in the secondary spectrum, which in PSRs J0613$-$0200 and J1600$-$3053 can be tracked between observations, and are consistent with compact scattering at fixed angular positions. Other sources such as PSRs J1643$-$1224 and J0621+1002 show diffuse, asymmetric arcs which are likely related to phase-gradients across the scattering screen. PSR B1937+21 shows at least three distinct screens which dominate at different times and evidence of varying screen axes or multi-screen interactions. We model annual and orbital arc curvature variations in PSR J0613$-$0200, providing a measurement of the longitude of ascending node, resolving the sense of the orbital inclination, where our best fit model is of a screen with variable axis of anisotropy over time, corresponding to changes in the scattering of the source. Unmodeled variations of the screen's axis of anisotropy are likely to be a limiting factor in determining orbital parameters with scintillation, requiring careful consideration of variable screen properties, or independent VLBI measurements. Long-term scintillation studies such as this serve as a complementary tool to pulsar timing, to measure a source of correlated noise for pulsar timing arrays, solve pulsar orbits, and to understand the astrophysical origin of scattering screens., Comment: Submitted to MNRAS, first revision. 18 pages, 16 figures
Published: 2023
Full Text: View/download PDF

14. Practical approaches to analyzing PTA data: Cosmic strings with six pulsars

Author: Leclere, Hippolyte Quelquejay, Auclair, Pierre, Babak, Stanislav, Chalumeau, Aurélien, Steer, Danièle A., Antoniadis, J., Nielsen, A. -S. Bak, Bassa, C. G., Berthereau, A., Bonetti, M., Bortolas, E., Brook, P. R., Burgay, M., Caballero, R. N., Champion, D. J., Chanlaridis, S., Chen, S., Cognard, I., Desvignes, G., Falxa, M., Ferdman, R. D., Franchini, A., Gair, J. R., Goncharov, B., Graikou, E., Grießmeier, J. -M., Guillemot, L., Guo, Y. J., Hu, H., Iraci, F., Izquierdo-Villalba, D., Jang, J., Jawor, J., Janssen, G. H., Jessner, A., Karuppusamy, R., Keane, E. F., Keith, M. J., Kramer, M., Krishnakumar, M. A., Lackeos, K., Lee, K. J., Liu, K., Liu, Y., Lyne, A. G., McKee, J. W., Main, R. A., Mickaliger, M. B., Niţu, I. C., Parthasarathy, A., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Samajdar, A., Sanidas, S. A., Sesana, A., Shaifullah, G., Speri, L., Spiewak, R., Stappers, B. W., Susarla, S. C., Theureau, G., Tiburzi, C., van der Wateren, E., Vecchio, A., Krishnan, V. Venkatraman, Verbiest, J. P. W., Wang, J., Wang, L., and Wu, Z.
Subjects: General Relativity and Quantum Cosmology, Astrophysics - Cosmology and Nongalactic Astrophysics, High Energy Physics - Theory
Abstract: We search for a stochastic gravitational wave background (SGWB) generated by a network of cosmic strings using six millisecond pulsars from Data Release 2 (DR2) of the European Pulsar Timing Array (EPTA). We perform a Bayesian analysis considering two models for the network of cosmic string loops, and compare it to a simple power-law model which is expected from the population of supermassive black hole binaries. Our main strong assumption is that the previously reported common red noise process is a SGWB. We find that the one-parameter cosmic string model is slightly favored over a power-law model thanks to its simplicity. If we assume a two-component stochastic signal in the data (supermassive black hole binary population and the signal from cosmic strings), we get a $95\%$ upper limit on the string tension of $\log_{10}(G\mu) < -9.9$ ($-10.5$) for the two cosmic string models we consider. In extended two-parameter string models, we were unable to constrain the number of kinks. We test two approximate and fast Bayesian data analysis methods against the most rigorous analysis and find consistent results. These two fast and efficient methods are applicable to all SGWBs, independent of their source, and will be crucial for analysis of extended data sets., Comment: 14 pages, 6 figures; typo corrected in (5)
Published: 2023
Full Text: View/download PDF

15. Searching for continuous Gravitational Waves in the second data release of the International Pulsar Timing Array

Author: Falxa, M., Babak, S., Baker, P. T., Bécsy, B., Chalumeau, A., Chen, S., Chen, Z., Cornish, N. J., Guillemot, L., Hazboun, J. S., Mingarelli, C. M. F., Parthasarathy, A., Petiteau, A., Pol, N. S., Sesana, A., Spolaor, S. B., Taylor, S. R., Theureau, G., Vallisneri, M., Vigeland, S. J., Witt, C. A., Zhu, X., Antoniadis, J., Arzoumanian, Z., Bailes, M., Bhat, N. D. R., Blecha, L., Brazier, A., Brook, P. R., Caballero, N., Cameron, A. D., Casey-Clyde, J. A., Champion, D., Charisi, M., Chatterjee, S., Cognard, I., Cordes, J. M., Crawford, F., Cromartie, H. T., Crowter, K., Dai, S., DeCesar, M. E., Demorest, P. B., Desvignes, G., Dolch, T., Drachler, B., Feng, Y., Ferrara, E. C., Fiore, W., Fonseca, E., Garver-Daniels, N., Glaser, J., Goncharov, B., Good, D. C., Griessmeier, J., Guo, Y. J., Gültekin, K., Hobbs, G., Hu, H., Islo, K., Jang, J., Jennings, R. J., Johnson, A. D., Jones, M. L., Kaczmarek, J., Kaiser, A. R., Kaplan, D. L., Keith, M., Kelley, L. Z., Kerr, M., Key, J. S., Laal, N., Lam, M. T., Lamb, W. G., Lazio, T. J. W., Liu, K., Liu, T., Luo, J., Lynch, R. S., Madison, D. R., Main, R., Manchester, R., McEwen, A., McKee, J., McLaughlin, M. A., Ng, C., Nice, D. J., Ocker, S., Olum, K. D., Osłowski, S., Pennucci, T. T., Perera, B. B. P., Perrodin, D., Porayko, N., Possenti, A., Quelquejay-Leclere, H., Ransom, S. M., Ray, P. S., Reardon, D. J., Russell, C. J., Samajdar, A., Sarkissian, J., Schult, L., Shaifullah, G., Shannon, R. M., Shapiro-Albert, B. J., Siemens, X., Simon, J. J., Siwek, M., Smith, T. L., Speri, L., Spiewak, R., Stairs, I. H., Stappers, B., Stinebring, D. R., Swiggum, J. K., Tiburzi, C., Turner, J., Vecchio, A., Verbiest, J. P. W., Wahl, H., Wang, S. Q., Wang, J., Wu, Z., Zhang, L., and Zhang, S.
Subjects: General Relativity and Quantum Cosmology, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The International Pulsar Timing Array 2nd data release is the combination of datasets from worldwide collaborations. In this study, we search for continuous waves: gravitational wave signals produced by individual supermassive black hole binaries in the local universe. We consider binaries on circular orbits and neglect the evolution of orbital frequency over the observational span. We find no evidence for such signals and set sky averaged 95% upper limits on their amplitude h 95 . The most sensitive frequency is 10nHz with h 95 = 9.1 10-15 . We achieved the best upper limit to date at low and high frequencies of the PTA band thanks to improved effective cadence of observations. In our analysis, we have taken into account the recently discovered common red noise process, which has an impact at low frequencies. We also find that the peculiar noise features present in some pulsars data must be taken into account to reduce the false alarm. We show that using custom noise models is essential in searching for continuous gravitational wave signals and setting the upper limit.
Published: 2023
Full Text: View/download PDF

16. A new pulsar timing model for scalar-tensor gravity with applications to PSR J2222-0137 and pulsar-black hole binaries

Author: Batrakov, A., Hu, H., Wex, N., Freire, P. C. C., Krishnan, V. Venkatraman, Kramer, M., Guo, Y. J., Guillemot, L., McKee, J. W., Cognard, I., and Theureau, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics, General Relativity and Quantum Cosmology
Abstract: Context. Scalar-tensor gravity (STG) theories are well-motivated alternatives to general relativity (GR). One class of STG theories, the Damour-Esposito-Farese (DEF) gravity, has a massless scalar field with two arbitrary coupling parameters. We are interested in this theory because, despite its simplicity, it predicts a wealth of different phenomena, such as dipolar gravitational wave emission and spontaneous scalarization of neutron stars (NSs). These phenomena of DEF gravity can be tested by timing binary radio pulsars. Aims. We aim to develop a new binary pulsar timing model DDSTG to enable more precise tests of STG theories based on a minimal set of binary parameters. The expressions for post-Keplerian (PK) parameters in DEF gravity are self-consistently incorporated into the model. The new technique takes into account all possible correlations between PK parameters naturally. Methods. Grids of physical parameters of NSs are calculated in the framework of DEF gravity for a set of 11 equations of state. The automatic Differentiation (AutoDiff) technique is employed, which aids in the calculation of gravitational form factors of NSs with higher precision than in previous works. The pulsar timing program TEMPO is selected as a framework for the realization of the DDSTG model. The implemented model is applicable to any type of pulsar companions. Results. We apply the DDSTG model to the most recently published observational data for PSR J2222-0137. The obtained limits on DEF gravity parameters for this system confirm and improve previous results. New limits are also the most reliable because DEF gravity is directly fitted to the data. We argue that future observations of PSR J2222-0137 can significantly improve the limits and that PSR-BH systems have the potential to place the tightest limits in certain areas of the DEF gravity parameter space., Comment: Accepted to Astronomy and Astrophysics on 09.02.2023
Published: 2023

17. Scattering variability detected from the circumsource medium of FRB 20190520B

Author: Ocker, S. K., Cordes, J. M., Chatterjee, S., Li, D., Niu, C. H., McKee, J. W., Law, C. J., and Anna-Thomas, R.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: Fast radio bursts (FRBs) are millisecond-timescale radio transients, the origins of which are predominantly extragalactic and likely involve highly magnetized compact objects. FRBs undergo multipath propagation, or scattering, from electron density fluctuations on sub-parsec scales in ionized gas along the line-of-sight. Scattering observations have located plasma structures within FRB host galaxies, probed Galactic and extragalactic turbulence, and constrained FRB redshifts. Scattering also inhibits FRB detection and biases the observed FRB population. We report the detection of scattering times from the repeating FRB 20190520B that vary by up to a factor of two or more on minutes to days-long timescales. In one notable case, the scattering time varied from $7.9\pm0.4$ ms to less than 3.1 ms ($95\%$ confidence) over 2.9 minutes at 1.45 GHz. The scattering times appear to be uncorrelated between bursts or with dispersion and rotation measure variations. Scattering variations are attributable to dynamic, inhomogeneous plasma in the circumsource medium, and analogous variations have been observed from the Crab pulsar. Under such circumstances, the frequency dependence of scattering can deviate from the typical power-law used to measure scattering. Similar variations may therefore be detectable from other FRBs, even those with inconspicuous scattering, providing a unique probe of small-scale processes within FRB environments., Comment: 10 pages, 9 figures, accepted to MNRAS
Published: 2022
Full Text: View/download PDF

18. CHIME Discovery of a Binary Pulsar with a Massive Non-Degenerate Companion

Author: Andersen, Bridget C., Fonseca, Emmanuel, McKee, J. W., Meyers, B. W., Luo, Jing, Tan, C. M., Stairs, I. H., Kaspi, Victoria M., van Kerkwijk, M. H., Bhardwaj, Mohit, Boyle, P. J., Crowter, Kathryn, Demorest, Paul B., Dong, Fengqui A., Good, Deborah C., Kaczmarek, Jane F., Leung, Calvin, Masui, Kiyoshi W., Naidu, Arun, Ng, Cherry, Patel, Chitrang, Pearlman, Aaron B., Pleunis, Ziggy, Rafiei-Ravandi, Masoud, Rahman, Mubdi, Ransom, Scott M., Smith, Kendrick M., and Tendulkar, Shriharsh P.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: Of the more than $3{,}000$ radio pulsars currently known, only ${\sim}300$ are in binary systems, and only five of these consist of young pulsars with massive non-degenerate companions. We present the discovery and initial timing, accomplished using the Canadian Hydrogen Intensity Mapping Experiment telescope (CHIME), of the sixth such binary pulsar, PSR J2108+4516, a $0.577$-s radio pulsar in a 269-day orbit of eccentricity 0.09 with a companion of minimum mass $11$ M$_{\odot}$. Notably, the pulsar undergoes periods of substantial eclipse, disappearing from the CHIME $400{-}800$ MHz observing band for a large fraction of its orbit, and displays significant dispersion measure and scattering variations throughout its orbit, pointing to the possibility of a circumstellar disk or very dense stellar wind associated with the companion star. Subarcsecond resolution imaging with the Karl G. Jansky Very Large Array unambiguously demonstrates that the companion is a bright, $V \simeq 11$ OBe star, EM* UHA 138, located at a distance of $3.26(14)$ kpc. Archival optical observations of \companion{} approximately suggest a companion mass ranging from $17.5$ M$_{\odot} < M_{\rm c} < 23$ M$_{\odot}$, in turn constraining the orbital inclination angle to $50.3^{\circ} \lesssim i \lesssim 58.3^{\circ}$. With further multi-wavelength followup, PSR J2108+4516 promises to serve as another rare laboratory for the exploration of companion winds, circumstellar disks, and short-term evolution through extended-body orbital dynamics., Comment: 20 pages, 12 figures, accepted by ApJ
Published: 2022
Full Text: View/download PDF

19. Detection of quasi-periodic micro-structure in three millisecond pulsars with the Large European Array for Pulsars

Author: Liu, K., Antoniadis, J., Bassa, C. G., Chen, S., Cognard, I., Gaikwad, M., Hu, H., Jang, J., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., Main, R. A., Mall, G., McKee, J. W., Mickaliger, M. B., Perrodin, D., Sanidas, S. A., Stappers, B. W., Wang, L., Zhu, W. W., Burgay, M., Concu, R., Corongiu, A., Melis, A., Pilia, M., and Possenti, A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: We report on the detection of quasi-periodic micro-structure in three millisecond pulsars (MSPs), PSRs J1022+1001, J2145-0750 and J1744-1134, using high time resolution data acquired with the Large European Array for Pulsars at a radio frequency of 1.4 GHz. The occurrence rate of quasi-periodic micro-structure is consistent among pulses with different peak flux densities. Using an auto-correlation analysis, we measure the periodicity and width of the micro-structure in these three pulsars. The detected micro-structure from PSRs J1022+1001 and J1744-1134 is often highly linearly polarised. In PSR J1022+1001, the linear polarisation position angles of micro-structure pulses are in general flat with a small degree of variation. Using these results, we further examine the frequency and rotational period dependency of micro-structure properties established in previous work, along with the angular beaming and temporal modulation models that explains the appearance of micro-structure. We also discuss a possible link of micro-structure to the properties of some of the recently discovered fast radio bursts which exhibit a very similar emission morphology., Comment: 8 pages, 6 figures, 1 table, published in MNRAS
Published: 2022
Full Text: View/download PDF

20. Robust parameter estimation from pulsar timing data

Author: Samajdar, A., Shaifullah, G., Sesana, A., Antoniadis, J., Burgay, M., Champion, D. J., Chen, S., Kramer, M., McKee, J. W., Mickaliger, M. B., and Van der Wateren, E.
Subjects: General Relativity and Quantum Cosmology
Abstract: Recently, global pulsar timing arrays have released results from searching for a nano-Hertz gravitational wave background signal. Although there has not been any definite evidence of the presence of such a signal in residuals of pulsar timing data yet, with more and improved data in future, a statistically significant detection is expected to be made. Stochastic algorithms are used to sample a very large parameter space to infer results from data. In this paper, we attempt to rule out effects arising from the stochasticity of the sampler in the inference process. We compare different configurations of nested samplers and the more commonly used markov chain monte carlo method to sample the pulsar timing array parameter space and account for times taken by the different samplers on same data. Although we obtain consistent results on parameters from different sampling algorithms, we propose two different samplers for robustness checks on data in the future to account for cross-checks between sampling methods as well as realistic run-times., Comment: 8 pages, 5 figures, 4 tables
Published: 2022
Full Text: View/download PDF

21. The Large Dispersion and Scattering of FRB 20190520B are Dominated by the Host Galaxy

Author: Ocker, S. K., Cordes, J. M., Chatterjee, S., Niu, C. -H., Li, D., McKee, J. W., Law, C. J., Tsai, C. -W., Anna-Thomas, R., Yao, J. -M., and Cruces, M.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The repeating FRB 20190520B is localized to a galaxy at $z=0.241$, much closer than expected given its dispersion measure $\rm DM=1205\pm4\ pc\ cm^{-3}$. Here we assess implications of the large DM and scattering observed from FRB 20190520B for the host galaxy's plasma properties. A sample of 75 bursts detected with the Five-hundred-meter Aperture Spherical radio Telescope shows scattering on two scales: a mean temporal delay $\tau(1.41\ {\rm GHz})=10.9\pm1.5$ ms, which is attributed to the host galaxy, and a mean scintillation bandwidth $\nu_{\rm d}(1.41\ {\rm GHz})=0.21\pm0.01$ MHz, which is attributed to the Milky Way. Balmer line measurements for the host imply an H$\alpha$ emission measure (galaxy frame) $\rm EM_s=620$ pc cm$^{-6} \times (T/10^4 {\rm K})^{0.9}$, implying $\rm DM_{\rm H\alpha}$ of order the value inferred from the FRB DM budget, $\rm DM_h=1121^{+89}_{-138}$ pc cm$^{-3}$ for plasma temperatures greater than the typical value $10^4$ K. Combining $\tau$ and $\rm DM_h$ yields a nominal constraint on the scattering amplification from the host galaxy $\tilde{F} G=1.5^{+0.8}_{-0.3}$ (pc$^2$ km)$^{-1/3}$, where $\tilde{F}$ describes turbulent density fluctuations and $G$ represents the geometric leverage to scattering that depends on the location of the scattering material. For a two-screen scattering geometry where $\tau$ arises from the host galaxy and $\Delta \nu_{\rm d}$ from the Milky Way, the implied distance between the FRB source and dominant scattering material is $\lesssim100$ pc. The host galaxy scattering and DM contributions support a novel technique for estimating FRB redshifts using the $\tau-\rm DM$ relation, and are consistent with previous findings that scattering of localized FRBs is largely dominated by plasma within host galaxies and the Milky Way., Comment: 14 pages, 9 figures, accepted to ApJ
Published: 2022
Full Text: View/download PDF

22. Modelling annual scintillation arc variations in PSR J1643-1224 using the Large European Array for Pulsars

Author: Mall, G., Main, R. A., Antoniadis, J., Bassa, C. G., Burgay, M., Chen, S., Cognard, I., Concu, R., Corongiu, A., Gaikwad, M., Hu, H., Janssen, G. H., Karuppusamy, R., Lee, K. J., Liu, K., McKee, J. W., Melis, A., Mickaliger, M. B., Perrodin, D., Pilia, M., Possenti, A., Reardon, D. J., Sanidas, S. A., Sprenger, T., Stappers, B. W., Wang, L., Wucknitz, O., and Zhu, W. W.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, High Energy Physics - Phenomenology
Abstract: In this work we study variations in the parabolic scintillation arcs of the binary millisecond pulsar PSR J1643-1224 over five years using the Large European Array for Pulsars (LEAP). The 2D power spectrum of scintillation, called the secondary spectrum, often shows a parabolic distribution of power, where the arc curvature encodes the relative velocities and distances of the pulsar, ionised interstellar medium (IISM), and Earth. We observe a clear parabolic scintillation arc which varies in curvature throughout the year. The distribution of power in the secondary spectra are inconsistent with a single scattering screen which is fully 1D, or entirely isotropic. We fit the observed arc curvature variations with two models; an isotropic scattering screen, and a model with two independent 1D screens. We measure the distance to the scattering screen to be in the range 114-223 pc, depending on the model, consistent with the known distance of the foreground large-diameter HII region Sh 2-27 (112+/-17 pc), suggesting that it is the dominant source of scattering. We obtain only weak constraints on the pulsar's orbital inclination and angle of periastron, since the scintillation pattern is not very sensitive to the pulsar's motion, since the screen is much closer to the Earth than the pulsar. More measurements of this kind - where scattering screens can be associated with foreground objects - will help to inform the origins and distribution of scattering screens within our galaxy., Comment: 11 pages, 6 figures. Accepted by MNRAS
Published: 2022
Full Text: View/download PDF

23. The International Pulsar Timing Array second data release: Search for an isotropic Gravitational Wave Background

Author: Antoniadis, J., Arzoumanian, Z., Babak, S., Bailes, M., Nielsen, A. -S. Bak, Baker, P. T., Bassa, C. G., Becsy, B., Berthereau, A., Bonetti, M., Brazier, A., Brook, P. R., Burgay, M., Burke-Spolaor, S., Caballero, R. N., Casey-Clyde, J. A., Chalumeau, A., Champion, D. J., Charisi, M., Chatterjee, S., Chen, S., Cognard, I., Cordes, J. M., Cornish, N. J., Crawford, F., Cromartie, H. T., Crowter, K., Dai, S., DeCesar, M. E., Demorest, P. B., Desvignes, G., Dolch, T., Drachler, B., Falxa, M., Ferrara, E. C., Fiore, W., Fonseca, E., Gair, J. R., Garver-Daniels, N., Goncharov, B., Good, D. C., Graikou, E., Guillemot, L., Guo, Y. J., Hazboun, J. S., Hobbs, G., Hu, H., Islo, K., Janssen, G. H., Jennings, R. J., Johnson, A. D., Jones, M. L., Kaiser, A. R., Kaplan, D. L., Karuppusamy, R., Keith, M. J., Kelley, L. Z., Kerr, M., Key, J. S., Kramer, M., Lam, M. T., Lamb, W. G., Lazio, T. J. W., Lee, K. J., Lentati, L., Liu, K., Luo, J., Lynch, R. S., Lyne, A. G., Madison, D. R., Main, R. A., Manchester, R. N., McEwen, A., McKee, J. W., McLaughlin, M. A., Mickaliger, M. B., Mingarelli, C. M. F., Ng, C., Nice, D. J., lowski, S. Os, Parthasarathy, A., Pennucci, T. T., Perera, B. B. P., Perrodin, D., Petiteau, A., Pol, N. S., Porayko, N. K., Possenti, A., Ransom, S. M., Ray, P. S., Reardon, D. J., Russell, C. J., Samajdar, A., Sampson, L. M., Sanidas, S., Sarkissian, J. M., Schmitz, K., Schult, L., Sesana, A., Shaifullah, G., Shannon, R. M., Shapiro-Albert, B. J., Siemens, X., Simon, J., Smith, T. L., Speri, L., Spiewak, R., Stairs, I. H., Stappers, B. W., Stinebring, D. R., Swiggum, J. K., Taylor, S. R., Theureau, G., Tiburzi, C., Vallisneri, M., van der Wateren, E., Vecchio, A., Verbiest, J. P. W., Vigeland, S. J., Wahl, H., Wang, J. B., Wang, J., Wang, L., Witt, C. A., Zhang, S., and Zhu, X. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: We searched for an isotropic stochastic gravitational wave background in the second data release of the International Pulsar Timing Array, a global collaboration synthesizing decadal-length pulsar-timing campaigns in North America, Europe, and Australia. In our reference search for a power law strain spectrum of the form $h_c = A(f/1\,\mathrm{yr}^{-1})^{\alpha}$, we found strong evidence for a spectrally-similar low-frequency stochastic process of amplitude $A = 3.8^{+6.3}_{-2.5}\times10^{-15}$ and spectral index $\alpha = -0.5 \pm 0.5$, where the uncertainties represent 95\% credible regions, using information from the auto- and cross-correlation terms between the pulsars in the array. For a spectral index of $\alpha = -2/3$, as expected from a population of inspiralling supermassive black hole binaries, the recovered amplitude is $A = 2.8^{+1.2}_{-0.8}\times10^{-15}$. Nonetheless, no significant evidence of the Hellings-Downs correlations that would indicate a gravitational-wave origin was found. We also analyzed the constituent data from the individual pulsar timing arrays in a consistent way, and clearly demonstrate that the combined international data set is more sensitive. Furthermore, we demonstrate that this combined data set produces comparable constraints to recent single-array data sets which have more data than the constituent parts of the combination. Future international data releases will deliver increased sensitivity to gravitational wave radiation, and significantly increase the detection probability., Comment: 17 pages, 12 figures, accepted in MNRAS
Published: 2022
Full Text: View/download PDF

24. Narrowband searches for continuous and long-duration transient gravitational waves from known pulsars in the LIGO-Virgo third observing run

Author: The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, Abbott, R., Abbott, T. D., Acernese, F., Ackley, K., Adams, C., Adhikari, N., Adhikari, R. X., Adya, V. B., Affeldt, C., Agarwal, D., Agathos, M., Agatsuma, K., Aggarwal, N., Aguiar, O. D., Aiello, L., Ain, A., Ajith, P., Akutsu, T., Albanesi, S., Allocca, A., Altin, P. A., Amato, A., Anand, C., Anand, S., Ananyeva, A., Anderson, S. B., Anderson, W. G., Ando, M., Andrade, T., Andres, N., Andrić, T., Angelova, S. V., Ansoldi, S., Antelis, J. M., Antier, S., Appert, S., Arai, Koji, Arai, Koya, Arai, Y., Araki, S., Araya, A., Araya, M. C., Areeda, J. S., Arène, M., Aritomi, N., Arnaud, N., Aronson, S. M., Arun, K. G., Asada, H., Asali, Y., Ashton, G., Aso, Y., Assiduo, M., Aston, S. M., Astone, P., Aubin, F., Austin, C., Babak, S., Badaracco, F., Bader, M. K. M., Badger, C., Bae, S., Bae, Y., Baer, A. M., Bagnasco, S., Bai, Y., Bailes, M., Baiotti, L., Baird, J., Bajpai, R., Ball, M., Ballardin, G., Ballmer, S. W., Balsamo, A., Baltus, G., Banagiri, S., Bankar, D., Barayoga, J. C., Barbieri, C., Barish, B. C., Barker, D., Barneo, P., Barone, F., Barr, B., Barsotti, L., Barsuglia, M., Barta, D., Bartlett, J., Barton, M. A., Bartos, I., Bassiri, R., Basti, A., Bawaj, M., Bayley, J. C., Baylor, A. C., Bazzan, M., Bécsy, B., Bedakihale, V. M., Bejger, M., Belahcene, I., Benedetto, V., Beniwal, D., Bennett, T. F., Bentley, J. D., BenYaala, M., Bergamin, F., Berger, B. K., Bernuzzi, S., Bersanetti, D., Bertolini, A., Betzwieser, J., Beveridge, D., Bhandare, R., Bhardwaj, U., Bhattacharjee, D., Bhaumik, S., Bilenko, I. A., Billingsley, G., Bini, S., Birney, R., Birnholtz, O., Biscans, S., Bischi, M., Biscoveanu, S., Bisht, A., Biswas, B., Bitossi, M., Bizouard, M. -A., Blackburn, J. K., Blair, C. D., Blair, D. G., Blair, R. M., Bobba, F., Bode, N., Boer, M., Bogaert, G., Boldrini, M., Bonavena, L. D., Bondu, F., Bonilla, E., Bonnand, R., Booker, P., Boom, B. A., Bork, R., Boschi, V., Bose, N., Bose, S., Bossilkov, V., Boudart, V., Bouffanais, Y., Bozzi, A., Bradaschia, C., Brady, P. R., Bramley, A., Branch, A., Branchesi, M., Brau, J. E., Breschi, M., Briant, T., Briggs, J. H., Brillet, A., Brinkmann, M., Brockill, P., Brooks, A. F., Brooks, J., Brown, D. D., Brunett, S., Bruno, G., Bruntz, R., Bryant, J., Bulik, T., Bulten, H. J., Buonanno, A., Buscicchio, R., Buskulic, D., Buy, C., Byer, R. L., Cadonati, L., Cagnoli, G., Cahillane, C., Bustillo, J. Calderón, Callaghan, J. D., Callister, T. A., Calloni, E., Cameron, J., Camp, J. B., Canepa, M., Canevarolo, S., Cannavacciuolo, M., Cannon, K. C., Cao, H., Cao, Z., Capocasa, E., Capote, E., Carapella, G., Carbognani, F., Carlin, J. B., Carney, M. F., Carpinelli, M., Carrillo, G., Carullo, G., Carver, T. L., Diaz, J. Casanueva, Casentini, C., Castaldi, G., Caudill, S., Cavaglià, M., Cavalier, F., Cavalieri, R., Ceasar, M., Cella, G., Cerdá-Durán, P., Cesarini, E., Chaibi, W., Chakravarti, K., Subrahmanya, S. Chalathadka, Champion, E., Chan, C. -H., Chan, C., Chan, C. L., Chan, K., Chan, M., Chandra, K., Chanial, P., Chao, S., Charlton, P., Chase, E. A., Chassande-Mottin, E., Chatterjee, C., Chatterjee, Debarati, Chatterjee, Deep, Chaturvedi, M., Chaty, S., Chen, C., Chen, H. Y., Chen, J., Chen, K., Chen, X., Chen, Y. -B., Chen, Y. -R., Chen, Z., Cheng, H., Cheong, C. K., Cheung, H. Y., Chia, H. Y., Chiadini, F., Chiang, C-Y., Chiarini, G., Chierici, R., Chincarini, A., Chiofalo, M. L., Chiummo, A., Cho, G., Cho, H. S., Choudhary, R. K., Choudhary, S., Christensen, N., Chu, H., Chu, Q., Chu, Y-K., Chua, S., Chung, K. W., Ciani, G., Ciecielag, P., Cieślar, M., Cifaldi, M., Ciobanu, A. A., Ciolfi, R., Cipriano, F., Cirone, A., Clara, F., Clark, E. N., Clark, J. A., Clarke, L., Clearwater, P., Clesse, S., Cleva, F., Coccia, E., Codazzo, E., Cohadon, P. -F., Cohen, D. E., Cohen, L., Colleoni, M., Collette, C. G., Colombo, A., Colpi, M., Compton, C. M., Constancio Jr., M., Conti, L., Cooper, S. J., Corban, P., Corbitt, T. R., Cordero-Carrión, I., Corezzi, S., Corley, K. R., Cornish, N., Corre, D., Corsi, A., Cortese, S., Costa, C. A., Cotesta, R., Coughlin, M. W., Coulon, J. -P., Countryman, S. T., Cousins, B., Couvares, P., Coward, D. M., Cowart, M. J., Coyne, D. C., Coyne, R., Creighton, J. D. E., Creighton, T. D., Criswell, A. W., Croquette, M., Crowder, S. G., Cudell, J. R., Cullen, T. J., Cumming, A., Cummings, R., Cunningham, L., Cuoco, E., Curyło, M., Dabadie, P., Canton, T. Dal, Dall'Osso, S., Dálya, G., Dana, A., DaneshgaranBajastani, L. M., D'Angelo, B., Danilishin, S., D'Antonio, S., Danzmann, K., Darsow-Fromm, C., Dasgupta, A., Datrier, L. E. H., Datta, S., Dattilo, V., Dave, I., Davier, M., Davies, G. S., Davis, D., Davis, M. C., Daw, E. J., Dean, R., DeBra, D., Deenadayalan, M., Degallaix, J., De Laurentis, M., Deléglise, S., Del Favero, V., De Lillo, F., De Lillo, N., Del Pozzo, W., DeMarchi, L. M., De Matteis, F., D'Emilio, V., Demos, N., Dent, T., Depasse, A., De Pietri, R., De Rosa, R., De Rossi, C., DeSalvo, R., De Simone, R., Dhurandhar, S., Díaz, M. C., Diaz-Ortiz Jr., M., Didio, N. A., Dietrich, T., Di Fiore, L., Di Fronzo, C., Di Giorgio, C., Di Giovanni, F., Di Giovanni, M., Di Girolamo, T., Di Lieto, A., Ding, B., Di Pace, S., Di Palma, I., Di Renzo, F., Divakarla, A. K., Dmitriev, A., Doctor, Z., D'Onofrio, L., Donovan, F., Dooley, K. L., Doravari, S., Dorrington, I., Drago, M., Driggers, J. C., Drori, Y., Ducoin, J. -G., Dupej, P., Durante, O., D'Urso, D., Duverne, P. -A., Dwyer, S. E., Eassa, C., Easter, P. J., Ebersold, M., Eckhardt, T., Eddolls, G., Edelman, B., Edo, T. B., Edy, O., Effler, A., Eguchi, S., Eichholz, J., Eikenberry, S. S., Eisenmann, M., Eisenstein, R. A., Ejlli, A., Engelby, E., Enomoto, Y., Errico, L., Essick, R. C., Estellés, H., Estevez, D., Etienne, Z., Etzel, T., Evans, M., Evans, T. M., Ewing, B. E., Fafone, V., Fair, H., Fairhurst, S., Farah, A. M., Farinon, S., Farr, B., Farr, W. M., Farrow, N. W., Fauchon-Jones, E. J., Favaro, G., Favata, M., Fays, M., Fazio, M., Feicht, J., Fejer, M. M., Fenyvesi, E., Ferguson, D. L., Fernandez-Galiana, A., Ferrante, I., Ferreira, T. A., Fidecaro, F., Figura, P., Fiori, I., Fishbach, M., Fisher, R. P., Fittipaldi, R., Fiumara, V., Flaminio, R., Floden, E., Fong, H., Font, J. A., Fornal, B., Forsyth, P. W. F., Franke, A., Frasca, S., Frasconi, F., Frederick, C., Freed, J. P., Frei, Z., Freise, A., Frey, R., Fritschel, P., Frolov, V. V., Fronzé, G. G., Fujii, Y., Fujikawa, Y., Fukunaga, M., Fukushima, M., Fulda, P., Fyffe, M., Gabbard, H. A., Gadre, B. U., Gair, J. R., Gais, J., Galaudage, S., Gamba, R., Ganapathy, D., Ganguly, A., Gao, D., Gaonkar, S. G., Garaventa, B., García-Núñez, C., García-Quirós, C., Garufi, F., Gateley, B., Gaudio, S., Gayathri, V., Ge, G. -G., Gemme, G., Gennai, A., George, J., Gerberding, O., Gergely, L., Gewecke, P., Ghonge, S., Ghosh, Abhirup, Ghosh, Archisman, Ghosh, Shaon, Ghosh, Shrobana, Giacomazzo, B., Giacoppo, L., Giaime, J. A., Giardina, K. D., Gibson, D. R., Gier, C., Giesler, M., Giri, P., Gissi, F., Glanzer, J., Gleckl, A. E., Godwin, P., Goetz, E., Goetz, R., Gohlke, N., Goncharov, B., González, G., Gopakumar, A., Gosselin, M., Gouaty, R., Gould, D. W., Grace, B., Grado, A., Granata, M., Granata, V., Grant, A., Gras, S., Grassia, P., Gray, C., Gray, R., Greco, G., Green, A. C., Green, R., Gretarsson, A. M., Gretarsson, E. M., Griffith, D., Griffiths, W., Griggs, H. L., Grignani, G., Grimaldi, A., Grimm, S. J., Grote, H., Grunewald, S., Gruning, P., Guerra, D., Guidi, G. M., Guimaraes, A. R., Guixé, G., Gulati, H. K., Guo, H. -K., Guo, Y., Gupta, Anchal, Gupta, Anuradha, Gupta, P., Gustafson, E. K., Gustafson, R., Guzman, F., Ha, S., Haegel, L., Hagiwara, A., Haino, S., Halim, O., Hall, E. D., Hamilton, E. Z., Hammond, G., Han, W. -B., Haney, M., Hanks, J., Hanna, C., Hannam, M. D., Hannuksela, O., Hansen, H., Hansen, T. J., Hanson, J., Harder, T., Hardwick, T., Haris, K., Harms, J., Harry, G. M., Harry, I. W., Hartwig, D., Hasegawa, K., Haskell, B., Hasskew, R. K., Haster, C. -J., Hattori, K., Haughian, K., Hayakawa, H., Hayama, K., Hayes, F. J., Healy, J., Heidmann, A., Heidt, A., Heintze, M. C., Heinze, J., Heinzel, J., Heitmann, H., Hellman, F., Hello, P., Helmling-Cornell, A. F., Hemming, G., Hendry, M., Heng, I. S., Hennes, E., Hennig, J., Hennig, M. H., Hernandez, A. G., Vivanco, F. Hernandez, Heurs, M., Hild, S., Hill, P., Himemoto, Y., Hines, A. S., Hiranuma, Y., Hirata, N., Hirose, E., Ho, W. C. G., Hochheim, S., Hofman, D., Hohmann, J. N., Holcomb, D. G., Holland, N. A., Hollows, I. J., Holmes, Z. J., Holt, K., Holz, D. E., Hong, Z., Hopkins, P., Hough, J., Hourihane, S., Howell, E. J., Hoy, C. G., Hoyland, D., Hreibi, A., Hsieh, B-H., Hsu, Y., Huang, G-Z., Huang, H-Y., Huang, P., Huang, Y-C., Huang, Y. -J., Huang, Y., Hübner, M. T., Huddart, A. D., Hughey, B., Hui, D. C. Y., Hui, V., Husa, S., Huttner, S. H., Huxford, R., Huynh-Dinh, T., Ide, S., Idzkowski, B., Iess, A., Ikenoue, B., Imam, S., Inayoshi, K., Ingram, C., Inoue, Y., Ioka, K., Isi, M., Isleif, K., Ito, K., Itoh, Y., Iyer, B. R., Izumi, K., JaberianHamedan, V., Jacqmin, T., Jadhav, S. J., Jadhav, S. P., James, A. L., Jan, A. Z., Jani, K., Janquart, J., Janssens, K., Janthalur, N. N., Jaranowski, P., Jariwala, D., Jaume, R., Jenkins, A. C., Jenner, K., Jeon, C., Jeunon, M., Jia, W., Jin, H. -B., Johns, G. R., Jones, A. W., Jones, D. I., Jones, J. D., Jones, P., Jones, R., Jonker, R. J. G., Ju, L., Jung, P., Jung, k., Junker, J., Juste, V., Kaihotsu, K., Kajita, T., Kakizaki, M., Kalaghatgi, C. V., Kalogera, V., Kamai, B., Kamiizumi, M., Kanda, N., Kandhasamy, S., Kang, G., Kanner, J. B., Kao, Y., Kapadia, S. J., Kapasi, D. P., Karat, S., Karathanasis, C., Karki, S., Kashyap, R., Kasprzack, M., Kastaun, W., Katsanevas, S., Katsavounidis, E., Katzman, W., Kaur, T., Kawabe, K., Kawaguchi, K., Kawai, N., Kawasaki, T., Kéfélian, F., Keitel, D., Key, J. S., Khadka, S., Khalili, F. Y., Khan, S., Khazanov, E. A., Khetan, N., Khursheed, M., Kijbunchoo, N., Kim, C., Kim, J. C., Kim, J., Kim, K., Kim, W. S., Kim, Y. -M., Kimball, C., Kimura, N., Kinley-Hanlon, M., Kirchhoff, R., Kissel, J. S., Kita, N., Kitazawa, H., Kleybolte, L., Klimenko, S., Knee, A. M., Knowles, T. D., Knyazev, E., Koch, P., Koekoek, G., Kojima, Y., Kokeyama, K., Koley, S., Kolitsidou, P., Kolstein, M., Komori, K., Kondrashov, V., Kong, A. K. H., Kontos, A., Koper, N., Korobko, M., Kotake, K., Kovalam, M., Kozak, D. B., Kozakai, C., Kozu, R., Kringel, V., Krishnendu, N. V., Królak, A., Kuehn, G., Kuei, F., Kuijer, P., Kumar, A., Kumar, P., Kumar, Rahul, Kumar, Rakesh, Kume, J., Kuns, K., Kuo, C., Kuo, H-S., Kuromiya, Y., Kuroyanagi, S., Kusayanagi, K., Kuwahara, S., Kwak, K., Lagabbe, P., Laghi, D., Lalande, E., Lam, T. L., Lamberts, A., Landry, M., Lane, B. B., Lang, R. N., Lange, J., Lantz, B., La Rosa, I., Lartaux-Vollard, A., Lasky, P. D., Laxen, M., Lazzarini, A., Lazzaro, C., Leaci, P., Leavey, S., Lecoeuche, Y. K., Lee, H. K., Lee, H. M., Lee, H. W., Lee, J., Lee, K., Lee, R., Lehmann, J., Lemaître, A., Leonardi, M., Leroy, N., Letendre, N., Levesque, C., Levin, Y., Leviton, J. N., Leyde, K., Li, A. K. Y., Li, B., Li, J., Li, K. L., Li, T. G. F., Li, X., Lin, C-Y., Lin, F-K., Lin, F-L., Lin, H. L., Lin, L. C. -C., Linde, F., Linker, S. D., Linley, J. N., Littenberg, T. B., Liu, G. C., Liu, J., Liu, K., Liu, X., Llamas, F., Llorens-Monteagudo, M., Lo, R. K. L., Lockwood, A., London, L. T., Longo, A., Lopez, D., Portilla, M. Lopez, Lorenzini, M., Loriette, V., Lormand, M., Losurdo, G., Lott, T. P., Lough, J. D., Lousto, C. O., Lovelace, G., Lucaccioni, J. F., Lück, H., Lumaca, D., Lundgren, A. P., Luo, L. -W., Lynam, J. E., Macas, R., MacInnis, M., Macleod, D. M., MacMillan, I. A. O., Macquet, A., Hernandez, I. Magaña, Magazzù, C., Magee, R. M., Maggiore, R., Magnozzi, M., Mahesh, S., Majorana, E., Makarem, C., Maksimovic, I., Maliakal, S., Malik, A., Man, N., Mandic, V., Mangano, V., Mango, J. L., Mansell, G. L., Manske, M., Mantovani, M., Mapelli, M., Marchesoni, F., Marchio, M., Marion, F., Mark, Z., Márka, S., Márka, Z., Markakis, C., Markosyan, A. S., Markowitz, A., Maros, E., Marquina, A., Marsat, S., Martelli, F., Martin, I. W., Martin, R. M., Martinez, M., Martinez, V. A., Martinez, V., Martinovic, K., Martynov, D. V., Marx, E. J., Masalehdan, H., Mason, K., Massera, E., Masserot, A., Massinger, T. J., Masso-Reid, M., Mastrogiovanni, S., Matas, A., Mateu-Lucena, M., Matichard, F., Matiushechkina, M., Mavalvala, N., McCann, J. J., McCarthy, R., McClelland, D. E., McClincy, P. K., McCormick, S., McCuller, L., McGhee, G. I., McGuire, S. C., McIsaac, C., McIver, J., McRae, T., McWilliams, S. T., Meacher, D., Mehmet, M., Mehta, A. K., Meijer, Q., Melatos, A., Melchor, D. A., Mendell, G., Menendez-Vazquez, A., Menoni, C. S., Mercer, R. A., Mereni, L., Merfeld, K., Merilh, E. L., Merritt, J. D., Merzougui, M., Meshkov, S., Messenger, C., Messick, C., Meyers, P. M., Meylahn, F., Mhaske, A., Miani, A., Miao, H., Michaloliakos, I., Michel, C., Michimura, Y., Middleton, H., Milano, L., Miller, A. L., Miller, A., Miller, B., Millhouse, M., Mills, J. C., Milotti, E., Minazzoli, O., Minenkov, Y., Mio, N., Mir, Ll. M., Miravet-Tenés, M., Mishra, C., Mishra, T., Mistry, T., Mitra, S., Mitrofanov, V. P., Mitselmakher, G., Mittleman, R., Miyakawa, O., Miyamoto, A., Miyazaki, Y., Miyo, K., Miyoki, S., Mo, Geoffrey, Modafferi, L. M., Moguel, E., Mogushi, K., Mohapatra, S. R. P., Mohite, S. R., Molina, I., Molina-Ruiz, M., Mondin, M., Montani, M., Moore, C. J., Moragues, J., Moraru, D., Morawski, F., More, A., Moreno, C., Moreno, G., Mori, Y., Morisaki, S., Moriwaki, Y., Mours, B., Mow-Lowry, C. M., Mozzon, S., Muciaccia, F., Mukherjee, Arunava, Mukherjee, D., Mukherjee, Soma, Mukherjee, Subroto, Mukherjee, Suvodip, Mukund, N., Mullavey, A., Munch, J., Muñiz, E. A., Murray, P. G., Musenich, R., Muusse, S., Nadji, S. L., Nagano, K., Nagano, S., Nagar, A., Nakamura, K., Nakano, H., Nakano, M., Nakashima, R., Nakayama, Y., Napolano, V., Nardecchia, I., Narikawa, T., Naticchioni, L., Nayak, B., Nayak, R. K., Negishi, R., Neil, B. F., Neilson, J., Nelemans, G., Nelson, T. J. N., Nery, M., Neubauer, P., Neunzert, A., Ng, K. Y., Ng, S. W. S., Nguyen, C., Nguyen, P., Nguyen, T., Quynh, L. Nguyen, Ni, W. -T., Nichols, S. A., Nishizawa, A., Nissanke, S., Nitoglia, E., Nocera, F., Norman, M., North, C., Nozaki, S., Nuttall, L. K., Oberling, J., O'Brien, B. D., Obuchi, Y., O'Dell, J., Oelker, E., Ogaki, W., Oganesyan, G., Oh, J. J., Oh, K., Oh, S. H., Ohashi, M., Ohishi, N., Ohkawa, M., Ohme, F., Ohta, H., Okada, M. A., Okutani, Y., Okutomi, K., Olivetto, C., Oohara, K., Ooi, C., Oram, R., O'Reilly, B., Ormiston, R. G., Ormsby, N. D., Ortega, L. F., O'Shaughnessy, R., O'Shea, E., Oshino, S., Ossokine, S., Osthelder, C., Otabe, S., Ottaway, D. J., Overmier, H., Pace, A. E., Pagano, G., Page, M. A., Pagliaroli, G., Pai, A., Pai, S. A., Palamos, J. R., Palashov, O., Palomba, C., Pan, H., Pan, K., Panda, P. K., Pang, H., Pang, P. T. H., Pankow, C., Pannarale, F., Pant, B. C., Panther, F. H., Paoletti, F., Paoli, A., Paolone, A., Parisi, A., Park, H., Park, J., Parker, W., Pascucci, D., Pasqualetti, A., Passaquieti, R., Passuello, D., Patel, M., Pathak, M., Patricelli, B., Patron, A. S., Paul, S., Payne, E., Pedraza, M., Pegoraro, M., Pele, A., Arellano, F. E. Peña, Penn, S., Perego, A., Pereira, A., Pereira, T., Perez, C. J., Périgois, C., Perkins, C. C., Perreca, A., Perriès, S., Petermann, J., Petterson, D., Pfeiffer, H. P., Pham, K. A., Phukon, K. S., Piccinni, O. J., Pichot, M., Piendibene, M., Piergiovanni, F., Pierini, L., Pierro, V., Pillant, G., Pillas, M., Pilo, F., Pinard, L., Pinto, I. M., Pinto, M., Piotrzkowski, K., Pirello, M., Pitkin, M. D., Placidi, E., Planas, L., Plastino, W., Pluchar, C., Poggiani, R., Polini, E., Pong, D. Y. T., Ponrathnam, S., Popolizio, P., Porter, E. K., Poulton, R., Powell, J., Pracchia, M., Pradier, T., Prajapati, A. K., Prasai, K., Prasanna, R., Pratten, G., Principe, M., Prodi, G. A., Prokhorov, L., Prosposito, P., Prudenzi, L., Puecher, A., Punturo, M., Puosi, F., Puppo, P., Pürrer, M., Qi, H., Quetschke, V., Quitzow-James, R., Raab, F. J., Raaijmakers, G., Radkins, H., Radulesco, N., Raffai, P., Rail, S. X., Raja, S., Rajan, C., Ramirez, K. E., Ramirez, T. D., Ramos-Buades, A., Rana, J., Rapagnani, P., Rapol, U. D., Ray, A., Raymond, V., Raza, N., Razzano, M., Read, J., Rees, L. A., Regimbau, T., Rei, L., Reid, S., Reid, S. W., Reitze, D. H., Relton, P., Renzini, A., Rettegno, P., Rezac, M., Ricci, F., Richards, D., Richardson, J. W., Richardson, L., Riemenschneider, G., Riles, K., Rinaldi, S., Rink, K., Rizzo, M., Robertson, N. A., Robie, R., Robinet, F., Rocchi, A., Rodriguez, S., Rolland, L., Rollins, J. G., Romanelli, M., Romano, R., Romel, C. L., Romero-Rodríguez, A., Romero-Shaw, I. M., Romie, J. H., Ronchini, S., Rosa, L., Rose, C. A., Rosińska, D., Ross, M. P., Rowan, S., Rowlinson, S. J., Roy, S., Roy, Santosh, Roy, Soumen, Rozza, D., Ruggi, P., Ryan, K., Sachdev, S., Sadecki, T., Sadiq, J., Sago, N., Saito, S., Saito, Y., Sakai, K., Sakai, Y., Sakellariadou, M., Sakuno, Y., Salafia, O. S., Salconi, L., Saleem, M., Salemi, F., Samajdar, A., Sanchez, E. J., Sanchez, J. H., Sanchez, L. E., Sanchis-Gual, N., Sanders, J. R., Sanuy, A., Saravanan, T. R., Sarin, N., Sassolas, B., Satari, H., Sato, S., Sato, T., Sauter, O., Savage, R. L., Sawada, T., Sawant, D., Sawant, H. L., Sayah, S., Schaetzl, D., Scheel, M., Scheuer, J., Schiworski, M., Schmidt, P., Schmidt, S., Schnabel, R., Schneewind, M., Schofield, R. M. S., Schönbeck, A., Schulte, B. W., Schutz, B. F., Schwartz, E., Scott, J., Scott, S. M., Seglar-Arroyo, M., Sekiguchi, T., Sekiguchi, Y., Sellers, D., Sengupta, A. S., Sentenac, D., Seo, E. G., Sequino, V., Sergeev, A., Setyawati, Y., Shaffer, T., Shahriar, M. S., Shams, B., Shao, L., Sharma, A., Sharma, P., Shawhan, P., Shcheblanov, N. S., Shibagaki, S., Shikauchi, M., Shimizu, R., Shimoda, T., Shimode, K., Shinkai, H., Shishido, T., Shoda, A., Shoemaker, D. H., Shoemaker, D. M., ShyamSundar, S., Sieniawska, M., Sigg, D., Singer, L. P., Singh, D., Singh, N., Singha, A., Sintes, A. M., Sipala, V., Skliris, V., Slagmolen, B. J. J., Slaven-Blair, T. J., Smetana, J., Smith, J. R., Smith, R. J. E., Soldateschi, J., Somala, S. N., Somiya, K., Son, E. J., Soni, K., Soni, S., Sordini, V., Sorrentino, F., Sorrentino, N., Sotani, H., Soulard, R., Souradeep, T., Sowell, E., Spagnuolo, V., Spencer, A. P., Spera, M., Srinivasan, R., Srivastava, A. K., Srivastava, V., Staats, K., Stachie, C., Steer, D. A., Steinlechner, J., Steinlechner, S., Stops, D. J., Stover, M., Strain, K. A., Strang, L. C., Stratta, G., Strunk, A., Sturani, R., Stuver, A. L., Sudhagar, S., Sudhir, V., Sugimoto, R., Suh, H. G., Summerscales, T. Z., Sun, H., Sun, L., Sunil, S., Sur, A., Suresh, J., Sutton, P. J., Suzuki, Takamasa, Suzuki, Toshikazu, Swinkels, B. L., Szczepańczyk, M. J., Szewczyk, P., Tacca, M., Tagoshi, H., Tait, S. C., Takahashi, H., Takahashi, R., Takamori, A., Takano, S., Takeda, H., Takeda, M., Talbot, C. J., Talbot, C., Tanaka, H., Tanaka, Kazuyuki, Tanaka, Kenta, Tanaka, Taiki, Tanaka, Takahiro, Tanasijczuk, A. J., Tanioka, S., Tanner, D. B., Tao, D., Tao, L., Martín, E. N. Tapia San, Taranto, C., Tasson, J. D., Telada, S., Tenorio, R., Terhune, J. E., Terkowski, L., Thirugnanasambandam, M. P., Thomas, M., Thomas, P., Thompson, J. E., Thondapu, S. R., Thorne, K. A., Thrane, E., Tiwari, Shubhanshu, Tiwari, Srishti, Tiwari, V., Toivonen, A. M., Toland, K., Tolley, A. E., Tomaru, T., Tomigami, Y., Tomura, T., Tonelli, M., Torres-Forné, A., Torrie, C. I., Melo, I. Tosta e, Töyrä, D., Trapananti, A., Travasso, F., Traylor, G., Trevor, M., Tringali, M. C., Tripathee, A., Troiano, L., Trovato, A., Trozzo, L., Trudeau, R. J., Tsai, D. S., Tsai, D., Tsang, K. W., Tsang, T., Tsao, J-S., Tse, M., Tso, R., Tsubono, K., Tsuchida, S., Tsukada, L., Tsuna, D., Tsutsui, T., Tsuzuki, T., Turbang, K., Turconi, M., Tuyenbayev, D., Ubhi, A. S., Uchikata, N., Uchiyama, T., Udall, R. P., Ueda, A., Uehara, T., Ueno, K., Ueshima, G., Unnikrishnan, C. S., Uraguchi, F., Urban, A. L., Ushiba, T., Utina, A., Vahlbruch, H., Vajente, G., Vajpeyi, A., Valdes, G., Valentini, M., Valsan, V., van Bakel, N., van Beuzekom, M., Brand, J. F. J. van den, Broeck, C. Van Den, Vander-Hyde, D. C., van der Schaaf, L., van Heijningen, J. V., Vanosky, J., van Putten, M. H. P. M., van Remortel, N., Vardaro, M., Vargas, A. F., Varma, V., Vasúth, M., Vecchio, A., Vedovato, G., Veitch, J., Veitch, P. J., Venneberg, J., Venugopalan, G., Verkindt, D., Verma, P., Verma, Y., Veske, D., Vetrano, F., Viceré, A., Vidyant, S., Viets, A. D., Vijaykumar, A., Villa-Ortega, V., Vinet, J. -Y., Virtuoso, A., Vitale, S., Vo, T., Vocca, H., von Reis, E. R. G., von Wrangel, J. S. A., Vorvick, C., Vyatchanin, S. P., Wade, L. E., Wade, M., Wagner, K. J., Walet, R. C., Walker, M., Wallace, G. S., Wallace, L., Walsh, S., Wang, J., Wang, J. Z., Wang, W. H., Ward, R. L., Warner, J., Was, M., Washimi, T., Washington, N. Y., Watchi, J., Weaver, B., Webster, S. A., Weinert, M., Weinstein, A. J., Weiss, R., Weller, C. M., Wellmann, F., Wen, L., Weßels, P., Wette, K., Whelan, J. T., White, D. D., Whiting, B. F., Whittle, C., Wilken, D., Williams, D., Williams, M. J., Williamson, A. R., Willis, J. L., Willke, B., Wilson, D. J., Winkler, W., Wipf, C. C., Wlodarczyk, T., Woan, G., Woehler, J., Wofford, J. K., Wong, I. C. F., Wu, C., Wu, D. S., Wu, H., Wu, S., Wysocki, D. M., Xiao, L., Xu, W-R., Yamada, T., Yamamoto, H., Yamamoto, Kazuhiro, Yamamoto, Kohei, Yamamoto, T., Yamashita, K., Yamazaki, R., Yang, F. W., Yang, L., Yang, Y., Yang, Yang, Yang, Z., Yap, M. J., Yeeles, D. W., Yelikar, A. B., Ying, M., Yokogawa, K., Yokoyama, J., Yokozawa, T., Yoo, J., Yoshioka, T., Yu, Hang, Yu, Haocun, Yuzurihara, H., Zadrożny, A., Zanolin, M., Zeidler, S., Zelenova, T., Zendri, J. -P., Zevin, M., Zhan, M., Zhang, H., Zhang, J., Zhang, L., Zhang, T., Zhang, Y., Zhao, C., Zhao, G., Zhao, Y., Zhao, Yue, Zhou, R., Zhou, Z., Zhu, X. J., Zhu, Z. -H., Zucker, M. E., Zweizig, J., Antonopoulou, D., Arzoumanian, Z., Basu, A., Bogdanov, S., Cognard, I., Crowter, K., Enoto, T., Espinoza, C. M., Flynn, C. M. L., Fonseca, E., Good, D. C., Guillemot, L., Guillot, S., Harding, A. K., Keith, M. J., Kuiper, L., Lower, M. E., Lyne, A. G., McKee, J. W., Meyers, B. W., Ng, C., Palfreyman, J. L., Shannon, R. M., Shaw, B., Stairs, I. H., Stappers, B. W., Tan, C. M., Theureau, G., and Weltevrede, P.
Subjects: General Relativity and Quantum Cosmology, Astrophysics - High Energy Astrophysical Phenomena
Abstract: Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully-coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow the frequency and frequency time-derivative of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets., Comment: 37 pages, 9 figures, submitted to ApJ
Published: 2021
Full Text: View/download PDF

25. Strong-field Gravity Tests with the Double Pulsar

Author: Kramer, M., Stairs, I. H., Manchester, R. N., Wex, N., Deller, A. T., Coles, W. A., Ali, M., Burgay, M., Camilo, F., Cognard, I., Damour, T., Desvignes, G., Ferdman, R. D., Freire, P. C. C., Grondin, S., Guillemot, L., Hobbs, G. B., Janssen, G., Karuppusamy, R., Lorimer, D. R., Lyne, A. G., McKee, J. W., McLaughlin, M., Muench, L. E., Perera, B. B. P., Pol, N., Possenti, A., Sarkissian, J., Stappers, B. W., and Theureau, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract: Continued observations of the Double Pulsar, PSR J0737-3039A/B, consisting of two radio pulsars (A and B) that orbit each other with a period of 2.45hr in a mildly eccentric (e=0.088) binary system, have led to large improvements in the measurement of relativistic effects in this system. With a 16-yr data span, the results enable precision tests of theories of gravity for strongly self-gravitating bodies and also reveal new relativistic effects that have been expected but are now observed for the first time. These include effects of light propagation in strong gravitational fields which are currently not testable by any other method. We observe retardation and aberrational light-bending that allow determination of the pulsar's spin direction. In total, we have detected seven post-Keplerian (PK) parameters, more than for any other binary pulsar. For some of these effects, the measurement precision is so high that for the first time we have to take higher-order contributions into account. These include contributions of A's effective mass loss (due to spin-down) to the observed orbital period decay, a relativistic deformation of the orbit, and effects of the equation of state of super-dense matter on the observed PK parameters via relativistic spin-orbit coupling. We discuss the implications of our findings, including those for the moment of inertia of neutron stars. We present the currently most precise test of general relativity's (GR's) quadrupolar description of gravitational waves, validating GR's prediction at a level of $1.3 \times 10^{-4}$ (95% conf.). We demonstrate the utility of the Double Pulsar for tests of alternative theories by focusing on two specific examples and discuss some implications for studies of the interstellar medium and models for the formation of the Double Pulsar. Finally, we provide context to other types of related experiments and prospects for the future., Comment: 56 pages, 23 Figures. Published by Physical Review X. Uploaded ArXiv version is authors' (pre-proof) version with abbreviated abstract. Resubmission for updated acknowledgement information. For final published version see https://link.aps.org/doi/10.1103/PhysRevX.11.041050
Published: 2021
Full Text: View/download PDF

26. Removal and replacement of interference in tied-array radio pulsar observations using the spectral kurtosis estimator

Author: Purver, M., Bassa, C. G., Cognard, I., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., Liu, K., McKee, J. W., Perrodin, D., Sanidas, S., Smits, R., and Stappers, B. W.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - High Energy Astrophysical Phenomena
Abstract: We describe how to implement the spectral kurtosis method of interference removal (zapping) on a digitized signal of averaged power values. Spectral kurtosis is a hypothesis test, analogous to the t-test, with a null hypothesis that the amplitudes from which power is formed belong to a `good' distribution -- typically Gaussian with zero mean -- where power values are zapped if the hypothesis is rejected at a specified confidence level. We derive signal-to-noise ratios (SNRs) as a function of amount of zapping for folded radio pulsar observations consisting of a sum of signals from multiple telescopes in independent radio-frequency interference (RFI) environments, comparing four methods to compensate for lost data with coherent (tied-array) and incoherent summation. For coherently summed amplitudes, scaling amplitudes from non-zapped telescopes achieves a higher SNR than replacing zapped amplitudes with artificial noise. For incoherently summed power values, the highest SNR is given by scaling power from non-zapped telescopes to maintain a constant mean. We use spectral kurtosis to clean a tied-array radio pulsar observation by the Large European Array for Pulsars (LEAP): the signal from one telescope is zapped with time and frequency resolutions of 6.25 $\mu$s and 0.16 MHz, removing interference along with 0.27 per cent of `good' data, giving an uncertainty of 0.25 $\mu$s in pulse time of arrival (TOA) for PSR J1022+1001. We use a single-telescope observation to demonstrate recovery of the pulse profile shape, with 0.6 per cent of data zapped and a reduction from 1.22 to 0.70 $\mu$s in TOA uncertainty., Comment: 16 pages, 9 figures
Published: 2021
Full Text: View/download PDF

27. Searches for Gravitational Waves from Known Pulsars at Two Harmonics in the Second and Third LIGO-Virgo Observing Runs

Author: The LIGO Scientific Collaboration, the Virgo Collaboration, the KAGRA Collaboration, Abbott, R., Abe, H., Acernese, F., Ackley, K., Adhikari, N., Adhikari, R. X., Adkins, V. K., Adya, V. B., Affeldt, C., Agarwal, D., Agathos, M., Agatsuma, K., Aggarwal, N., Aguiar, O. D., Aiello, L., Ain, A., Ajith, P., Akutsu, T., Albanesi, S., Alfaidi, R. A., Allocca, A., Altin, P. A., Amato, A., Anand, C., Anand, S., Ananyeva, A., Anderson, S. B., Anderson, W. G., Ando, M., Andrade, T., Andres, N., Andrés-Carcasona, M., Andrić, T., Angelova, S. V., Ansoldi, S., Antelis, J. M., Antier, S., Apostolatos, T., Appavuravther, E. Z., Appert, S., Apple, S. K., Arai, K., Araya, A., Araya, M. C., Areeda, J. S., Arène, M., Aritomi, N., Arnaud, N., Arogeti, M., Aronson, S. M., Arun, K. G., Asada, H., Asali, Y., Ashton, G., Aso, Y., Assiduo, M., Melo, S. Assis de Souza, Aston, S. M., Astone, P., Aubin, F., AultONeal, K., Austin, C., Babak, S., Badaracco, F., Bader, M. K. M., Badger, C., Bae, S., Bae, Y., Baer, A. M., Bagnasco, S., Bai, Y., Bailes, M., Baird, J., Bajpai, R., Baka, T., Ball, M., Ballardin, G., Ballmer, S. W., Balsamo, A., Baltus, G., Banagiri, S., Banerjee, B., Bankar, D., Barayoga, J. C., Barbieri, C., Barish, B. C., Barker, D., Barneo, P., Barone, F., Barr, B., Barsotti, L., Barsuglia, M., Barta, D., Bartlett, J., Barton, M. A., Bartos, I., Basak, S., Bassiri, R., Basti, A., Bawaj, M., Bayley, J. C., Bazzan, M., Becher, B. R., Bécsy, B., Bedakihale, V. M., Beirnaert, F., Bejger, M., Belahcene, I., Benedetto, V., Beniwal, D., Benjamin, M. G., Bennett, T. F., Bentley, J. D., BenYaala, M., Bera, S., Berbel, M., Bergamin, F., Berger, B. K., Bernuzzi, S., Bersanetti, D., Bertolini, A., Betzwieser, J., Beveridge, D., Bhandare, R., Bhandari, A. V., Bhardwaj, U., Bhatt, R., Bhattacharjee, D., Bhaumik, S., Bianchi, A., Bilenko, I. A., Billingsley, G., Bini, S., Birney, R., Birnholtz, O., Biscans, S., Bischi, M., Biscoveanu, S., Bisht, A., Biswas, B., Bitossi, M., Bizouard, M. -A., Blackburn, J. K., Blair, C. D., Blair, D. G., Blair, R. M., Bobba, F., Bode, N., Boër, M., Bogaert, G., Boldrini, M., Bolingbroke, G. N., Bonavena, L. D., Bondu, F., Bonilla, E., Bonnand, R., Booker, P., Boom, B. A., Bork, R., Boschi, V., Bose, N., Bose, S., Bossilkov, V., Boudart, V., Bouffanais, Y., Bozzi, A., Bradaschia, C., Brady, P. R., Bramley, A., Branch, A., Branchesi, M., Brau, J. E., Breschi, M., Briant, T., Briggs, J. H., Brillet, A., Brinkmann, M., Brockill, P., Brooks, A. F., Brooks, J., Brown, D. D., Brunett, S., Bruno, G., Bruntz, R., Bryant, J., Bucci, F., Bulik, T., Bulten, H. J., Buonanno, A., Burtnyk, K., Buscicchio, R., Buskulic, D., Buy, C., Byer, R. L., Davies, G. S. Cabourn, Cabras, G., Cabrita, R., Cadonati, L., Caesar, M., Cagnoli, G., Cahillane, C., Bustillo, J. Calderón, Callaghan, J. D., Callister, T. A., Calloni, E., Cameron, J., Camp, J. B., Canepa, M., Canevarolo, S., Cannavacciuolo, M., Cannon, K. C., Cao, H., Cao, Z., Capocasa, E., Capote, E., Carapella, G., Carbognani, F., Carlassara, M., Carlin, J. B., Carney, M. F., Carpinelli, M., Carrillo, G., Carullo, G., Carver, T. L., Diaz, J. Casanueva, Casentini, C., Castaldi, G., Caudill, S., Cavaglià, M., Cavalier, F., Cavalieri, R., Cella, G., Cerdá-Durán, P., Cesarini, E., Chaibi, W., Subrahmanya, S. Chalathadka, Champion, E., Chan, C. -H., Chan, C., Chan, C. L., Chan, K., Chan, M., Chandra, K., Chang, I. P., Chanial, P., Chao, S., Chapman-Bird, C., Charlton, P., Chase, E. A., Chassande-Mottin, E., Chatterjee, C., Chatterjee, Debarati, Chatterjee, Deep, Chaturvedi, M., Chaty, S., Chen, C., Chen, D., Chen, H. Y., Chen, J., Chen, K., Chen, X., Chen, Y. -B., Chen, Y. -R., Chen, Z., Cheng, H., Cheong, C. K., Cheung, H. Y., Chia, H. Y., Chiadini, F., Chiang, C-Y., Chiarini, G., Chierici, R., Chincarini, A., Chiofalo, M. L., Chiummo, A., Choudhary, R. K., Choudhary, S., Christensen, N., Chu, Q., Chu, Y-K., Chua, S. S. Y., Chung, K. W., Ciani, G., Ciecielag, P., Cieślar, M., Cifaldi, M., Ciobanu, A. A., Ciolfi, R., Cipriano, F., Clara, F., Clark, J. A., Clearwater, P., Clesse, S., Cleva, F., Coccia, E., Codazzo, E., Cohadon, P. -F., Cohen, D. E., Colleoni, M., Collette, C. G., Colombo, A., Colpi, M., Compton, C. M., Constancio Jr., M., Conti, L., Cooper, S. J., Corban, P., Corbitt, T. R., Cordero-Carrión, I., Corezzi, S., Corley, K. R., Cornish, N. J., Corre, D., Corsi, A., Cortese, S., Costa, C. A., Cotesta, R., Cottingham, R., Coughlin, M. W., Coulon, J. -P., Countryman, S. T., Cousins, B., Couvares, P., Coward, D. M., Cowart, M. J., Coyne, D. C., Coyne, R., Creighton, J. D. E., Creighton, T. D., Criswell, A. W., Croquette, M., Crowder, S. G., Cudell, J. R., Cullen, T. J., Cumming, A., Cummings, R., Cunningham, L., Cuoco, E., Curyło, M., Dabadie, P., Canton, T. Dal, Dall'Osso, S., Dálya, G., Dana, A., D'Angelo, B., Danilishin, S., D'Antonio, S., Danzmann, K., Darsow-Fromm, C., Dasgupta, A., Datrier, L. E. H., Datta, Sayak, Datta, Sayantani, Dattilo, V., Dave, I., Davier, M., Davis, D., Davis, M. C., Daw, E. J., Dean, R., DeBra, D., Deenadayalan, M., Degallaix, J., De Laurentis, M., Deléglise, S., Del Favero, V., De Lillo, F., De Lillo, N., Dell'Aquila, D., Del Pozzo, W., DeMarchi, L. M., De Matteis, F., D'Emilio, V., Demos, N., Dent, T., Depasse, A., De Pietri, R., De Rosa, R., De Rossi, C., DeSalvo, R., De Simone, R., Dhurandhar, S., Díaz, M. C., Didio, N. A., Dietrich, T., Di Fiore, L., Di Fronzo, C., Di Giorgio, C., Di Giovanni, F., Di Giovanni, M., Di Girolamo, T., Di Lieto, A., Di Michele, A., Ding, B., Di Pace, S., Di Palma, I., Di Renzo, F., Divakarla, A. K., Dmitriev, A., Doctor, Z., Donahue, L., D'Onofrio, L., Donovan, F., Dooley, K. L., Doravari, S., Drago, M., Driggers, J. C., Drori, Y., Ducoin, J. -G., Dupej, P., Dupletsa, U., Durante, O., D'Urso, D., Duverne, P. -A., Dwyer, S. E., Eassa, C., Easter, P. J., Ebersold, M., Eckhardt, T., Eddolls, G., Edelman, B., Edo, T. B., Edy, O., Effler, A., Eguchi, S., Eichholz, J., Eikenberry, S. S., Eisenmann, M., Eisenstein, R. A., Ejlli, A., Engelby, E., Enomoto, Y., Errico, L., Essick, R. C., Estellés, H., Estevez, D., Etienne, Z., Etzel, T., Evans, M., Evans, T. M., Evstafyeva, T., Ewing, B. E., Fabrizi, F., Faedi, F., Fafone, V., Fair, H., Fairhurst, S., Fan, P. C., Farah, A. M., Farinon, S., Farr, B., Farr, W. M., Fauchon-Jones, E. J., Favaro, G., Favata, M., Fays, M., Fazio, M., Feicht, J., Fejer, M. M., Fenyvesi, E., Ferguson, D. L., Fernandez-Galiana, A., Ferrante, I., Ferreira, T. A., Fidecaro, F., Figura, P., Fiori, A., Fiori, I., Fishbach, M., Fisher, R. P., Fittipaldi, R., Fiumara, V., Flaminio, R., Floden, E., Fong, H. K., Font, J. A., Fornal, B., Forsyth, P. W. F., Franke, A., Frasca, S., Frasconi, F., Freed, J. P., Frei, Z., Freise, A., Freitas, O., Frey, R., Fritschel, P., Frolov, V. V., Fronzé, G. G., Fujii, Y., Fujikawa, Y., Fujimoto, Y., Fulda, P., Fyffe, M., Gabbard, H. A., Gadre, B. U., Gair, J. R., Gais, J., Galaudage, S., Gamba, R., Ganapathy, D., Ganguly, A., Gao, D., Gaonkar, S. G., Garaventa, B., Núñez, C. García, García-Quirós, C., Garufi, F., Gateley, B., Gayathri, V., Ge, G. -G., Gemme, G., Gennai, A., George, J., Gerberding, O., Gergely, L., Gewecke, P., Ghonge, S., Ghosh, Abhirup, Ghosh, Archisman, Ghosh, Shaon, Ghosh, Shrobana, Ghosh, Tathagata, Giacomazzo, B., Giacoppo, L., Giaime, J. A., Giardina, K. D., Gibson, D. R., Gier, C., Giesler, M., Giri, P., Gissi, F., Gkaitatzis, S., Glanzer, J., Gleckl, A. E., Godwin, P., Goetz, E., Goetz, R., Gohlke, N., Golomb, J., Goncharov, B., González, G., Gosselin, M., Gouaty, R., Gould, D. W., Goyal, S., Grace, B., Grado, A., Graham, V., Granata, M., Granata, V., Grant, A., Gras, S., Grassia, P., Gray, C., Gray, R., Greco, G., Green, A. C., Green, R., Gretarsson, A. M., Gretarsson, E. M., Griffith, D., Griffiths, W. L., Griggs, H. L., Grignani, G., Grimaldi, A., Grimes, E., Grimm, S. J., Grote, H., Grunewald, S., Gruning, P., Gruson, A. S., Guerra, D., Guidi, G. M., Guimaraes, A. R., Guixé, G., Gulati, H. K., Gunny, A. M., Guo, H. -K., Guo, Y., Gupta, Anchal, Gupta, Anuradha, Gupta, I. M., Gupta, P., Gupta, S. K., Gustafson, R., Guzman, F., Ha, S., Hadiputrawan, I. P. W., Haegel, L., Haino, S., Halim, O., Hall, E. D., Hamilton, E. Z., Hammond, G., Han, W. -B., Haney, M., Hanks, J., Hanna, C., Hannam, M. D., Hannuksela, O., Hansen, H., Hansen, T. J., Hanson, J., Harder, T., Haris, K., Harms, J., Harry, G. M., Harry, I. W., Hartwig, D., Hasegawa, K., Haskell, B., Haster, C. -J., Hathaway, J. S., Hattori, K., Haughian, K., Hayakawa, H., Hayama, K., Hayes, F. J., Healy, J., Heidmann, A., Heidt, A., Heintze, M. C., Heinze, J., Heinzel, J., Heitmann, H., Hellman, F., Hello, P., Helmling-Cornell, A. F., Hemming, G., Hendry, M., Heng, I. S., Hennes, E., Hennig, J., Hennig, M. H., Henshaw, C., Hernandez, A. G., Vivanco, F. Hernandez, Heurs, M., Hewitt, A. L., Higginbotham, S., Hild, S., Hill, P., Himemoto, Y., Hines, A. S., Hirata, N., Hirose, C., Ho, T-C., Ho, W. C. G., Hochheim, S., Hofman, D., Hohmann, J. N., Holcomb, D. G., Holland, N. A., Hollows, I. J., Holmes, Z. J., Holt, K., Holz, D. E., Hong, Q., Hough, J., Hourihane, S., Howell, E. J., Hoy, C. G., Hoyland, D., Hreibi, A., Hsieh, B-H., Hsieh, H-F., Hsiung, C., Hsu, Y., Huang, H-Y., Huang, P., Huang, Y-C., Huang, Y. -J., Huang, Yiting, Huang, Yiwen, Hübner, M. T., Huddart, A. D., Hughey, B., Hui, D. C. Y., Hui, V., Husa, S., Huttner, S. H., Huxford, R., Huynh-Dinh, T., Ide, S., Idzkowski, B., Iess, A., Inayoshi, K., Inoue, Y., Iosif, P., Isi, M., Isleif, K., Ito, K., Itoh, Y., Iyer, B. R., JaberianHamedan, V., Jacqmin, T., Jacquet, P. -E., Jadhav, S. J., Jadhav, S. P., Jain, T., James, A. L., Jan, A. Z., Jani, K., Janquart, J., Janssens, K., Janthalur, N. N., Jaranowski, P., Jariwala, D., Jaume, R., Jenkins, A. C., Jenner, K., Jeon, C., Jia, W., Jiang, J., Jin, H. -B., Johns, G. R., Johnston, R., Jones, A. W., Jones, D. I., Jones, P., Jones, R., Joshi, P., Ju, L., Jue, A., Jung, P., Jung, K., Junker, J., Juste, V., Kaihotsu, K., Kajita, T., Kakizaki, M., Kalaghatgi, C. V., Kalogera, V., Kamai, B., Kamiizumi, M., Kanda, N., Kandhasamy, S., Kang, G., Kanner, J. B., Kao, Y., Kapadia, S. J., Kapasi, D. P., Karathanasis, C., Karki, S., Kashyap, R., Kasprzack, M., Kastaun, W., Kato, T., Katsanevas, S., Katsavounidis, E., Katzman, W., Kaur, T., Kawabe, K., Kawaguchi, K., Kéfélian, F., Keitel, D., Key, J. S., Khadka, S., Khalili, F. Y., Khan, S., Khanam, T., Khazanov, E. A., Khetan, N., Khursheed, M., Kijbunchoo, N., Kim, A., Kim, C., Kim, J. C., Kim, J., Kim, K., Kim, W. S., Kim, Y. -M., Kimball, C., Kimura, N., Kinley-Hanlon, M., Kirchhoff, R., Kissel, J. S., Klimenko, S., Klinger, T., Knee, A. M., Knowles, T. D., Knust, N., Knyazev, E., Kobayashi, Y., Koch, P., Koekoek, G., Kohri, K., Kokeyama, K., Koley, S., Kolitsidou, P., Kolstein, M., Komori, K., Kondrashov, V., Kong, A. K. H., Kontos, A., Koper, N., Korobko, M., Kovalam, M., Koyama, N., Kozak, D. B., Kozakai, C., Kringel, V., Krishnendu, N. V., Królak, A., Kuehn, G., Kuei, F., Kuijer, P., Kulkarni, S., Kumar, A., Kumar, Prayush, Kumar, Rahul, Kumar, Rakesh, Kume, J., Kuns, K., Kuromiya, Y., Kuroyanagi, S., Kwak, K., Lacaille, G., Lagabbe, P., Laghi, D., Lalande, E., Lalleman, M., Lam, T. L., Lamberts, A., Landry, M., Lane, B. B., Lang, R. N., Lange, J., Lantz, B., La Rosa, I., Lartaux-Vollard, A., Lasky, P. D., Laxen, M., Lazzarini, A., Lazzaro, C., Leaci, P., Leavey, S., LeBohec, S., Lecoeuche, Y. K., Lee, E., Lee, H. M., Lee, H. W., Lee, K., Lee, R., Legred, I. N., Lehmann, J., Lemaître, A., Lenti, M., Leonardi, M., Leonova, E., Leroy, N., Letendre, N., Levesque, C., Levin, Y., Leviton, J. N., Leyde, K., Li, A. K. Y., Li, B., Li, J., Li, K. L., Li, P., Li, T. G. F., Li, X., Lin, C-Y., Lin, E. T., Lin, F-K., Lin, F-L., Lin, H. L., Lin, L. C. -C., Linde, F., Linker, S. D., Linley, J. N., Littenberg, T. B., Liu, G. C., Liu, J., Liu, K., Liu, X., Llamas, F., Lo, R. K. L., Lo, T., London, L. T., Longo, A., Lopez, D., Portilla, M. Lopez, Lorenzini, M., Loriette, V., Lormand, M., Losurdo, G., Lott, T. P., Lough, J. D., Lousto, C. O., Lovelace, G., Lucaccioni, J. F., Lück, H., Lumaca, D., Lundgren, A. P., Luo, L. -W., Lynam, J. E., Ma'arif, M., Macas, R., Machtinger, J. B., MacInnis, M., Macleod, D. M., MacMillan, I. A. O., Macquet, A., Hernandez, I. Magaña, Magazzù, C., Magee, R. M., Maggiore, R., Magnozzi, M., Mahesh, S., Majorana, E., Maksimovic, I., Maliakal, S., Malik, A., Man, N., Mandic, V., Mangano, V., Mansell, G. L., Manske, M., Mantovani, M., Mapelli, M., Marchesoni, F., Pina, D. Marín, Marion, F., Mark, Z., Márka, S., Márka, Z., Markakis, C., Markosyan, A. S., Markowitz, A., Maros, E., Marquina, A., Marsat, S., Martelli, F., Martin, I. W., Martin, R. M., Martinez, M., Martinez, V. A., Martinez, V., Martinovic, K., Martynov, D. V., Marx, E. J., Masalehdan, H., Mason, K., Massera, E., Masserot, A., Masso-Reid, M., Mastrogiovanni, S., Matas, A., Mateu-Lucena, M., Matichard, F., Matiushechkina, M., Mavalvala, N., McCann, J. J., McCarthy, R., McClelland, D. E., McClincy, P. K., McCormick, S., McCuller, L., McGhee, G. I., McGuire, S. C., McIsaac, C., McIver, J., McRae, T., McWilliams, S. T., Meacher, D., Mehmet, M., Mehta, A. K., Meijer, Q., Melatos, A., Melchor, D. A., Mendell, G., Menendez-Vazquez, A., Menoni, C. S., Mercer, R. A., Mereni, L., Merfeld, K., Merilh, E. L., Merritt, J. D., Merzougui, M., Meshkov, S., Messenger, C., Messick, C., Meyers, P. M., Meylahn, F., Mhaske, A., Miani, A., Miao, H., Michaloliakos, I., Michel, C., Michimura, Y., Middleton, H., Mihaylov, D. P., Milano, L., Miller, A. L., Miller, A., Miller, B., Millhouse, M., Mills, J. C., Milotti, E., Minenkov, Y., Mio, N., Mir, Ll. M., Miravet-Tenés, M., Mishkin, A., Mishra, C., Mishra, T., Mistry, T., Mitra, S., Mitrofanov, V. P., Mitselmakher, G., Mittleman, R., Miyakawa, O., Miyo, K., Miyoki, S., Mo, Geoffrey, Modafferi, L. M., Moguel, E., Mogushi, K., Mohapatra, S. R. P., Mohite, S. R., Molina, I., Molina-Ruiz, M., Mondin, M., Montani, M., Moore, C. J., Moragues, J., Moraru, D., Morawski, F., More, A., Moreno, C., Moreno, G., Mori, Y., Morisaki, S., Morisue, N., Moriwaki, Y., Mours, B., Mow-Lowry, C. M., Mozzon, S., Muciaccia, F., Mukherjee, Arunava, Mukherjee, D., Mukherjee, Soma, Mukherjee, Subroto, Mukherjee, Suvodip, Mukund, N., Mullavey, A., Munch, J., Muñiz, E. A., Murray, P. G., Musenich, R., Muusse, S., Nadji, S. L., Nagano, K., Nagar, A., Nakamura, K., Nakano, H., Nakano, M., Nakayama, Y., Napolano, V., Nardecchia, I., Narikawa, T., Narola, H., Naticchioni, L., Nayak, B., Nayak, R. K., Neil, B. F., Neilson, J., Nelson, A., Nelson, T. J. N., Nery, M., Neubauer, P., Neunzert, A., Ng, K. Y., Ng, S. W. S., Nguyen, C., Nguyen, P., Nguyen, T., Quynh, L. Nguyen, Ni, J., Ni, W. -T., Nichols, S. A., Nishimoto, T., Nishizawa, A., Nissanke, S., Nitoglia, E., Nocera, F., Norman, M., North, C., Nozaki, S., Nurbek, G., Nuttall, L. K., Obayashi, Y., Oberling, J., O'Brien, B. D., O'Dell, J., Oelker, E., Ogaki, W., Oganesyan, G., Oh, J. J., Oh, K., Oh, S. H., Ohashi, M., Ohashi, T., Ohkawa, M., Ohme, F., Ohta, H., Okada, M. A., Okutani, Y., Olivetto, C., Oohara, K., Oram, R., O'Reilly, B., Ormiston, R. G., Ormsby, N. D., O'Shaughnessy, R., O'Shea, E., Oshino, S., Ossokine, S., Osthelder, C., Otabe, S., Ottaway, D. J., Overmier, H., Pace, A. E., Pagano, G., Pagano, R., Page, M. A., Pagliaroli, G., Pai, A., Pai, S. A., Pal, S., Palamos, J. R., Palashov, O., Palomba, C., Pan, H., Pan, K. -C., Panda, P. K., Pang, P. T. H., Pankow, C., Pannarale, F., Pant, B. C., Panther, F. H., Paoletti, F., Paoli, A., Paolone, A., Pappas, G., Parisi, A., Park, H., Park, J., Parker, W., Pascucci, D., Pasqualetti, A., Passaquieti, R., Passuello, D., Patel, M., Pathak, M., Patricelli, B., Patron, A. S., Paul, S., Payne, E., Pedraza, M., Pedurand, R., Pegoraro, M., Pele, A., Arellano, F. E. Peña, Penano, S., Penn, S., Perego, A., Pereira, A., Pereira, T., Perez, C. J., Périgois, C., Perkins, C. C., Perreca, A., Perriès, S., Pesios, D., Petermann, J., Petterson, D., Pfeiffer, H. P., Pham, H., Pham, K. A., Phukon, K. S., Phurailatpam, H., Piccinni, O. J., Pichot, M., Piendibene, M., Piergiovanni, F., Pierini, L., Pierro, V., Pillant, G., Pillas, M., Pilo, F., Pinard, L., Pineda-Bosque, C., Pinto, I. M., Pinto, M., Piotrzkowski, B. J., Piotrzkowski, K., Pirello, M., Pitkin, M. D., Placidi, A., Placidi, E., Planas, M. L., Plastino, W., Pluchar, C., Poggiani, R., Polini, E., Pong, D. Y. T., Ponrathnam, S., Porter, E. K., Poulton, R., Poverman, A., Powell, J., Pracchia, M., Pradier, T., Prajapati, A. K., Prasai, K., Prasanna, R., Pratten, G., Principe, M., Prodi, G. A., Prokhorov, L., Prosposito, P., Prudenzi, L., Puecher, A., Punturo, M., Puosi, F., Puppo, P., Pürrer, M., Qi, H., Quartey, N., Quetschke, V., Quinonez, P. J., Quitzow-James, R., Raab, F. J., Raaijmakers, G., Radkins, H., Radulesco, N., Raffai, P., Rail, S. X., Raja, S., Rajan, C., Ramirez, K. E., Ramirez, T. D., Ramos-Buades, A., Rana, J., Rapagnani, P., Ray, A., Raymond, V., Raza, N., Razzano, M., Read, J., Rees, L. A., Regimbau, T., Rei, L., Reid, S., Reid, S. W., Reitze, D. H., Relton, P., Renzini, A., Rettegno, P., Revenu, B., Reza, A., Rezac, M., Ricci, F., Richards, D., Richardson, J. W., Richardson, L., Riemenschneider, G., Riles, K., Rinaldi, S., Rink, K., Robertson, N. A., Robie, R., Robinet, F., Rocchi, A., Rodriguez, S., Rolland, L., Rollins, J. G., Romanelli, M., Romano, R., Romel, C. L., Romero, A., Romero-Shaw, I. M., Romie, J. H., Ronchini, S., Rosa, L., Rose, C. A., Rosińska, D., Ross, M. P., Rowan, S., Rowlinson, S. J., Roy, S., Roy, Santosh, Roy, Soumen, Rozza, D., Ruggi, P., Ruiz-Rocha, K., Ryan, K., Sachdev, S., Sadecki, T., Sadiq, J., Saha, S., Saito, Y., Sakai, K., Sakellariadou, M., Sakon, S., Salafia, O. S., Salces-Carcoba, F., Salconi, L., Saleem, M., Salemi, F., Samajdar, A., Sanchez, E. J., Sanchez, J. H., Sanchez, L. E., Sanchis-Gual, N., Sanders, J. R., Sanuy, A., Saravanan, T. R., Sarin, N., Sassolas, B., Satari, H., Sauter, O., Savage, R. L., Savant, V., Sawada, T., Sawant, H. L., Sayah, S., Schaetzl, D., Scheel, M., Scheuer, J., Schiworski, M. G., Schmidt, P., Schmidt, S., Schnabel, R., Schneewind, M., Schofield, R. M. S., Schönbeck, A., Schulte, B. W., Schutz, B. F., Schwartz, E., Scott, J., Scott, S. M., Seglar-Arroyo, M., Sekiguchi, Y., Sellers, D., Sengupta, A. S., Sentenac, D., Seo, E. G., Sequino, V., Sergeev, A., Setyawati, Y., Shaffer, T., Shahriar, M. S., Shaikh, M. A., Shams, B., Shao, L., Sharma, A., Sharma, P., Shawhan, P., Shcheblanov, N. S., Sheela, A., Shikano, Y., Shikauchi, M., Shimizu, H., Shimode, K., Shinkai, H., Shishido, T., Shoda, A., Shoemaker, D. H., Shoemaker, D. M., ShyamSundar, S., Sieniawska, M., Sigg, D., Silenzi, L., Singer, L. P., Singh, D., Singh, M. K., Singh, N., Singha, A., Sintes, A. M., Sipala, V., Skliris, V., Slagmolen, B. J. J., Slaven-Blair, T. J., Smetana, J., Smith, J. R., Smith, L., Smith, R. J. E., Soldateschi, J., Somala, S. N., Somiya, K., Song, I., Soni, K., Sordini, V., Sorrentino, F., Sorrentino, N., Soulard, R., Souradeep, T., Sowell, E., Spagnuolo, V., Spencer, A. P., Spera, M., Spinicelli, P., Srivastava, A. K., Srivastava, V., Staats, K., Stachie, C., Stachurski, F., Steer, D. A., Steinlechner, J., Steinlechner, S., Stergioulas, N., Stops, D. J., Stover, M., Strain, K. A., Strang, L. C., Stratta, G., Strong, M. D., Strunk, A., Sturani, R., Stuver, A. L., Suchenek, M., Sudhagar, S., Sudhir, V., Sugimoto, R., Suh, H. G., Sullivan, A. G., Summerscales, T. Z., Sun, L., Sunil, S., Sur, A., Suresh, J., Sutton, P. J., Suzuki, Takamasa, Suzuki, Takanori, Suzuki, Toshikazu, Swinkels, B. L., Szczepańczyk, M. J., Szewczyk, P., Tacca, M., Tagoshi, H., Tait, S. C., Takahashi, H., Takahashi, R., Takano, S., Takeda, H., Takeda, M., Talbot, C. J., Talbot, C., Tanaka, K., Tanaka, Taiki, Tanaka, Takahiro, Tanasijczuk, A. J., Tanioka, S., Tanner, D. B., Tao, D., Tao, L., Tapia, R. D., Martín, E. N. Tapia San, Taranto, C., Taruya, A., Tasson, J. D., Tenorio, R., Terhune, J. E. S., Terkowski, L., Thirugnanasambandam, M. P., Thomas, M., Thomas, P., Thompson, E. E., Thompson, J. E., Thondapu, S. R., Thorne, K. A., Thrane, E., Tiwari, Shubhanshu, Tiwari, Srishti, Tiwari, V., Toivonen, A. M., Tolley, A. E., Tomaru, T., Tomura, T., Tonelli, M., Tornasi, Z., Torres-Forné, A., Torrie, C. I., Melo, I. Tosta e, Töyrä, D., Trapananti, A., Travasso, F., Traylor, G., Trevor, M., Tringali, M. C., Tripathee, A., Troiano, L., Trovato, A., Trozzo, L., Trudeau, R. J., Tsai, D., Tsang, K. W., Tsang, T., Tsao, J-S., Tse, M., Tso, R., Tsuchida, S., Tsukada, L., Tsuna, D., Tsutsui, T., Turbang, K., Turconi, M., Tuyenbayev, D., Ubhi, A. S., Uchikata, N., Uchiyama, T., Udall, R. P., Ueda, A., Uehara, T., Ueno, K., Ueshima, G., Unnikrishnan, C. S., Urban, A. L., Ushiba, T., Utina, A., Vajente, G., Vajpeyi, A., Valdes, G., Valentini, M., Valsan, V., van Bakel, N., van Beuzekom, M., van Dael, M., Brand, J. F. J. van den, Broeck, C. Van Den, Vander-Hyde, D. C., van Haevermaet, H., van Heijningen, J. V., van Putten, M. H. P. M., van Remortel, N., Vardaro, M., Vargas, A. F., Varma, V., Vasúth, M., Vecchio, A., Vedovato, G., Veitch, J., Veitch, P. J., Venneberg, J., Venugopalan, G., Verkindt, D., Verma, P., Verma, Y., Vermeulen, S. M., Veske, D., Vetrano, F., Viceré, A., Vidyant, S., Viets, A. D., Vijaykumar, A., Villa-Ortega, V., Vinet, J. -Y., Virtuoso, A., Vitale, S., Vocca, H., von Reis, E. R. G., von Wrangel, J. S. A., Vorvick, C., Vyatchanin, S. P., Wade, L. E., Wade, M., Wagner, K. J., Walet, R. C., Walker, M., Wallace, G. S., Wallace, L., Wang, J., Wang, J. Z., Wang, W. H., Ward, R. L., Warner, J., Was, M., Washimi, T., Washington, N. Y., Watchi, J., Weaver, B., Weaving, C. R., Webster, S. A., Weinert, M., Weinstein, A. J., Weiss, R., Weller, C. M., Weller, R. A., Wellmann, F., Wen, L., Weßels, P., Wette, K., Whelan, J. T., White, D. D., Whiting, B. F., Whittle, C., Wilken, D., Williams, D., Williams, M. J., Williamson, A. R., Willis, J. L., Willke, B., Wilson, D. J., Wipf, C. C., Wlodarczyk, T., Woan, G., Woehler, J., Wofford, J. K., Wong, D., Wong, I. C. F., Wright, M., Wu, C., Wu, D. S., Wu, H., Wysocki, D. M., Xiao, L., Yamada, T., Yamamoto, H., Yamamoto, K., Yamamoto, T., Yamashita, K., Yamazaki, R., Yang, F. W., Yang, K. Z., Yang, L., Yang, Y. -C., Yang, Y., Yang, Yang, Yap, M. J., Yeeles, D. W., Yeh, S. -W., Yelikar, A. B., Ying, M., Yokoyama, J., Yokozawa, T., Yoo, J., Yoshioka, T., Yu, Hang, Yu, Haocun, Yuzurihara, H., Zadrożny, A., Zanolin, M., Zeidler, S., Zelenova, T., Zendri, J. -P., Zevin, M., Zhan, M., Zhang, H., Zhang, J., Zhang, L., Zhang, R., Zhang, T., Zhang, Y., Zhao, C., Zhao, G., Zhao, Y., Zhao, Yue, Zhou, R., Zhou, Z., Zhu, X. J., Zhu, Z. -H., Zucker, M. E., Zweizig, J., Antonopoulou, D., Arzoumanian, Z., Basu, A., Bogdanov, S., Cognard, I., Crowter, K., Enoto, T., Flynn, C. M. L., Good, D. C., Guillemot, L., Guillot, S., Harding, A. K., Keith, M. J., Kuiper, L., Lower, M. E., Lyne, A. G., McKee, J. W., Meyers, B. W., Palfreyman, J. L., Shannon, R. M., Shaw, B., Stairs, I. H., Stappers, B. W., Tan, C. M., Theureau, G., and Weltevrede, P.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, General Relativity and Quantum Cosmology
Abstract: We present a targeted search for continuous gravitational waves (GWs) from 236 pulsars using data from the third observing run of LIGO and Virgo (O3) combined with data from the second observing run (O2). Searches were for emission from the $l=m=2$ mass quadrupole mode with a frequency at only twice the pulsar rotation frequency (single harmonic) and the $l=2, m=1,2$ modes with a frequency of both once and twice the rotation frequency (dual harmonic). No evidence of GWs was found so we present 95\% credible upper limits on the strain amplitudes $h_0$ for the single harmonic search along with limits on the pulsars' mass quadrupole moments $Q_{22}$ and ellipticities $\varepsilon$. Of the pulsars studied, 23 have strain amplitudes that are lower than the limits calculated from their electromagnetically measured spin-down rates. These pulsars include the millisecond pulsars J0437\textminus4715 and J0711\textminus6830 which have spin-down ratios of 0.87 and 0.57 respectively. For nine pulsars, their spin-down limits have been surpassed for the first time. For the Crab and Vela pulsars our limits are factors of $\sim 100$ and $\sim 20$ more constraining than their spin-down limits, respectively. For the dual harmonic searches, new limits are placed on the strain amplitudes $C_{21}$ and $C_{22}$. For 23 pulsars we also present limits on the emission amplitude assuming dipole radiation as predicted by Brans-Dicke theory., Comment: 37 pages
Published: 2021
Full Text: View/download PDF

28. Noise analysis in the European Pulsar Timing Array data release 2 and its implications on the gravitational-wave background search

Author: Chalumeau, A., Babak, S., Petiteau, A., Chen, S., Samajdar, A., Caballero, R. N., Theureau, G., Guillemot, L., Desvignes, G., Parthasarathy, A., Liu, K., Shaifullah, G., Hu, H., van der Wateren, E., Antoniadis, J., Nielsen, A. -S. Bak, Bassa, C. G., Berthereau, A., Burgay, M., Champion, D. J., Cognard, I., Falxa, M., Ferdman, R. D., Freire, P. C. C., Gair, J. R., Graikou, E., Guo, Y. J., Jang, J., Janssen, G. H., Karuppusamy, R., Keith, M. J., Kramer, M., Lee, K. J., Liu, X. J., Lyne, A. G., Main, R. A., McKee, J. W., Mickaliger, M. B., Perera, B. B. P., Perrodin, D., Porayko, N. K., Possenti, A., Sanidas, S. A., Sesana, A., Speri, L., Stappers, B. W., Tiburzi, C., Vecchio, A., Verbiest, J. P. W., Wang, J., Wang, L., and Xu, H.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The European Pulsar Timing Array (EPTA) collaboration has recently released an extended data set for six pulsars (DR2) and reported evidence for a common red noise signal. Here we present a noise analysis for each of the six pulsars. We consider several types of noise: (i) radio frequency independent, "achromatic", and time-correlated red noise; (ii) variations of dispersion measure and scattering; (iii) system and band noise; and (iv) deterministic signals (other than gravitational waves) that could be present in the PTA data. We perform Bayesian model selection to find the optimal combination of noise components for each pulsar. Using these custom models we revisit the presence of the common uncorrelated red noise signal previously reported in the EPTA DR2 and show that the data still supports it with a high statistical significance. Next, we confirm that there is no preference for or against the Hellings-Downs spatial correlations expected for the stochastic gravitational-wave background. The main conclusion of the EPTA DR2 paper remains unchanged despite a very significant change in the noise model of each pulsar. However, modelling the noise is essential for the robust detection of gravitational waves and its impact could be significant when analysing the next EPTA data release, which will include a larger number of pulsars and more precise measurements., Comment: 21 pages, 11 figures, 7 tables, 1 appendix figure and 1 appendix table, accepted for publication to MNRAS
Published: 2021
Full Text: View/download PDF

29. 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: Chen, S., Caballero, R. N., Guo, Y. J., Chalumeau, A., Liu, K., Shaifullah, G., Lee, K. J., Babak, S., Desvignes, G., Parthasarathy, A., Hu, H., van der Wateren, E., Antoniadis, J., Nielsen, A. -S. Bak, Bassa, C. G., Berthereau, A., Burgay, M., Champion, D. J., Cognard, I., Falxa, M., Ferdman, R. D., Freire, P. C. C., Gair, J. R., Graikou, E., Guillemot, L., Jang, J., Janssen, G. H., Karuppusamy, R., Keith, M. J., Kramer, M., Liu, X. J., Lyne, A. G., Main, R. A., McKee, J. W., Mickaliger, M. B., Perera, B. B. P., Perrodin, D., Petiteau, A., Porayko, N. K., Possenti, A., Samajdar, A., Sanidas, S. A., Sesana, A., Speri, L., Stappers, B. W., Theureau, G., Tiburzi, C., Vecchio, A., Verbiest, J. P. W., Wang, J., Wang, L., and Xu, H.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, 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
Full Text: View/download PDF

30. Dual-frequency single-pulse study of PSR B0950+08

Author: Bilous, A. V., Griessmeier, J. M., Pennucci, T., Wu, Z., Bondonneau, L., Kondratiev, V., van Leeuwen, J., Maan, Y., Connor, L., Oostrum, L. C., Petroff, E., Verbiest, J. P. W., Vohl, D., McKee, J. W., Shaifullah, G., Theureau, G., Ulyanov, O. M., Cecconi, B., Coolen, A. H., Corbel, S., Damstra, S., Denes, H., Girard, J. N., Hut, B., Ivashina, M., Konovalenko, O. O., Kutkin, A., Loose, G. M., Mulder, H., Ruiter, M., Smits, R., Tokarsky, P. L., Vermaas, N. J., Zakharenko, V. V., Zarka, P., and Ziemke, J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract: PSR B0950+08 is a bright non-recycled pulsar whose single-pulse fluence variability is reportedly large. Based on observations at two widely separated frequencies, 55 MHz (NenuFAR) and 1.4 GHz (Westerbork Synthesis Radio Telescope), we review the properties of these single pulses. We conclude that they are more similar to ordinary pulses of radio emission than to a special kind of short and bright Giant Pulses, observed from only a handful of pulsars. We argue that temporal variation of properties of interstellar medium along the line of sight to this nearby pulsar, namely the fluctuating size of decorrelation bandwidth of diffractive scintillation makes important contribution to observed single-pulse fluence variability. We further present interesting structures in the low-frequency single-pulse spectra that resemble the "sad trombones" seen in Fast Radio Bursts (FRBs); although for PSR B0950+08 the upward frequency drift is also routinely present. We explain these spectral features with radius-to-frequency mapping, similar to the model developed by Wang et al. (2019) for FRBs. Finally, we speculate that microsecond-scale fluence variability of the general pulsar population remains poorly known, and that its further study may bring important clues about the nature of FRBs., Comment: Accepted by A&A. This version includes a number of minor corrections, including corrected FRB luminosities on the time-luminosity phase-space plot for radio pulses from neutron stars and repeating FRBs
Published: 2021
Full Text: View/download PDF

31. Study of 72 pulsars discovered in the PALFA survey: Timing analysis, glitch activity, emission variability, and a pulsar in an eccentric binary

Author: Parent, E., Sewalls, H., Freire, P. C. C., Matheny, T., Lyne, A. G., Perera, B. B. P., Cardoso, F., McLaughlin, M. A., Allen, B., Brazier, A., Camilo, F., Chatterjee, S., Cordes, J. M., Crawford, F., Deneva, J. S., Dong, F. A., Ferdman, R. D., Fonseca, E., Hessels, J. W. T., Kaspi, V. M., Knispel, B., van Leeuwen, J., Lynch, R. S., Meyers, B. M., McKee, J. W., Mickaliger, M. B., Patel, C., Ransom, S. M., Rochon, A., Scholz, P., Stairs, I. H., Stappers, B. W., Tan, C. M., and Zhu, W. W.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: We present new discoveries and results from long-term timing of 72 pulsars discovered in the Arecibo PALFA survey, including precise determination of astrometric and spin parameters, and flux density and scatter broadening measurements at 1.4 GHz. Notable discoveries include two young pulsars (characteristic ages $\sim$30 kyr) with no apparent supernova remnant associations, three mode changing, 12 nulling and two intermittent pulsars. We detected eight glitches in five pulsars. Among them is PSR J1939+2609, an apparently old pulsar (characteristic age $\sim$1 Gy), and PSR J1954+2529, which likely belongs to a newly-emerging class of binary pulsars. The latter is the only pulsar among the 72 that is clearly not isolated: a non-recycled neutron star with a 931-ms spin period in an eccentric ($e\,=\,0.114$) wide ($P_b\,=\,82.7\,$d) orbit with a companion of undetermined nature having a minimum mass of $\sim0.6\,M_{\odot}$. Since operations at Arecibo ceased in 2020 August, we give a final tally of PALFA sky coverage, and compare its 207 pulsar discoveries to the known population. On average, they are 50% more distant than other Galactic plane radio pulsars; PALFA millisecond pulsars (MSP) have twice the dispersion measure per unit spin period than the known population of MSP in the Plane. The four intermittent pulsars discovered by PALFA more than double the population of such objects, which should help to improve our understanding of pulsar magnetosphere physics. The statistics for these, RRATS, and nulling pulsars suggest that there are many more of these objects in the Galaxy than was previously thought., Comment: 39 pages, 18 figures, 9 tables. Accepted for publication in ApJ
Published: 2021
Full Text: View/download PDF

32. PSR J2222--0137. I. Improved physical parameters for the system

Author: Guo, Y. J., Freire, P. C. C., Guillemot, L., Kramer, M., Zhu, W. W., Wex, N., McKee, J. W., Deller, A., Ding, H., Kaplan, D. L., Stappers, B., Cognard, I., Miao, X., Haase, L., Keith, M., Ransom, S. M., and Theureau, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: The PSR J2222-0137 binary system is a unique laboratory for testing gravity theories. To fully exploit its potential for the tests, we aim to improve the measurements of its physical parameters: spin, orbital orientation, and post-Keplerian parameters which quantify the observed relativistic effects. We present improved analysis of archival VLBI data, using a coordinate convention in full agreement with that used in timing. We also obtain much improved polarimetry with FAST. We provide an analysis of significantly extended timing data taken with Effelsberg, Nancay, Lovell and Green Bank telescopes. From VLBI analysis we obtain a new estimate of the position angle of ascending node, Omega=189(19) deg, and a new position of the pulsar with more conservative uncertainty. The FAST polarimetry and in particular the detection of an interpulse, yield much improved estimate for the spin geometry of the pulsar, in particular an inclination of the spin axis of 84 deg. From the timing we obtain a new 1% test of general relativity (GR) from the agreement of the Shapiro delay and the advance rate of periastron. Assuming GR in a self-consistent analysis of all effects, we obtain much improved mass: 1.831(10) M_sun for the pulsar and 1.319(4) M_sun for the companion; the total mass, 3.150(14) M_sun confirms it as the most massive double degenerate binary known in the Galaxy. This analysis also yields the orbital orientation: the orbital inclination is 85.27(4) deg, indicating a close alignment between the spin of the pulsar and the orbital angular momentum; Omega = 188(6) deg, matching our VLBI result. We also obtain precise value of the orbital period derivative, 0.251(8)e-12 s s^-1, consistent with the expected variation of Doppler factor plus the orbital decay caused by emission of gravitational wave (GW) predicted by GR. This agreement introduces stringent constraint on the emission of dipolar GW., Comment: 17 pages, 8 figures, 7 tables, accepted for publication in A&A
Published: 2021
Full Text: View/download PDF

33. Dispersion measure variability for 36 millisecond pulsars at 150MHz with LOFAR

Author: Donner, J. Y., Verbiest, J. P. W., Tiburzi, C., Osłowski, S., Künsemöller, J., Nielsen, A. -S. Bak, Grießmeier, J. -M., Serylak, M., Kramer, M., Anderson, J. M., Wucknitz, O., Keane, E., Kondratiev, V., Sobey, C., McKee, J. W., Bilous, A. V., Breton, R. P., Brüggen, M., Ciardi, B., Hoeft, M., van Leeuwen, J., and Vocks, C.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
Abstract: Radio pulses from pulsars are affected by plasma dispersion, which results in a frequency-dependent propagation delay. Variations in the magnitude of this effect lead to an additional source of red noise in pulsar timing experiments, including pulsar timing arrays that aim to detect nanohertz gravitational waves. We aim to quantify the time-variable dispersion with much improved precision and characterise the spectrum of these variations. We use the pulsar timing technique to obtain highly precise dispersion measure (DM) time series. Our dataset consists of observations of 36 millisecond pulsars, which were observed for up to 7.1 years with the LOFAR telescope at a centre frequency of ~150 MHz. Seventeen of these sources were observed with a weekly cadence, while the rest were observed at monthly cadence. We achieve a median DM precision of the order of 10^-5 cm^-3 pc for a significant fraction of our sources. We detect significant variations of the DM in all pulsars with a median DM uncertainty of less than 2x10^-4 cm^-3 pc. The noise contribution to pulsar timing experiments at higher frequencies is calculated to be at a level of 0.1-10 us at 1.4 GHz over a timespan of a few years, which is in many cases larger than the typical timing precision of 1 us or better that PTAs aim for. We found no evidence for a dependence of DM on radio frequency for any of the sources in our sample. The DM time series we obtained using LOFAR could in principle be used to correct higher-frequency data for the variations of the dispersive delay. However, there is currently the practical restriction that pulsars tend to provide either highly precise times of arrival (ToAs) at 1.4 GHz or a high DM precision at low frequencies, but not both, due to spectral properties. Combining the higher-frequency ToAs with those from LOFAR to measure the infinite-frequency ToA and DM would improve the result., Comment: 16 pages, 8 figures, 2 tables
Published: 2020
Full Text: View/download PDF

34. A precise mass measurement of PSR J2045+3633

Author: McKee, J. W., Freire, P. C. C., Berezina, M., Champion, D. J., Cognard, I., Graikou, E., Guillemot, L., Keith, M. J., Kramer, M., Lyne, A. G., Stappers, B. W., Tauris, T. M., and Theureau, G.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract: We present the results of a timing analysis undertaken with the goal of obtaining an improved mass measurement of the recycled pulsar J2045+3633. Using regular high-cadence observations with the Effelsberg, Nan\c{c}ay, and Lovell radio telescopes, together with targeted campaigns with the Arecibo Telescope and Effelsberg, we have assembled a 6-yr timing data set for this pulsar. We measure highly significant values for the proper motion and the related rate of change of orbital semi-major axis ($\dot{x}$), and have obtained high precision values of the rate of advance of periastron time ($\dot{\omega}$), and two of the Shapiro delay parameters ($h_{3}$ and $\varsigma$). This has allowed us to improve the measurements of the pulsar and companion masses by an order of magnitude, yielding (with $1\sigma$ uncertainties) $1.251^{+0.021}_{-0.021}\,\text{M}_{\odot}$ for PSR J2045+3633, and $0.873^{+0.016}_{-0.014}\,\text{M}_{\odot}$ for its white dwarf companion, and has allowed us to place improved constraints on the geometrical orientation of the binary system. Using our measurements of the binary component masses and the orbital size, we consider possible evolutionary scenarios for the system., Comment: 17 pages, 6 figures, accepted for publication in MNRAS
Published: 2020
Full Text: View/download PDF

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

Author: Main, R. A., Sanidas, S. A., Antoniadis, J., Bassa, C., Chen, S., Cognard, I., Gaikwad, M., Hu, H., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., Liu, K., Mall, G., McKee, J. W., Mickaliger, M. B., Perrodin, D., Stappers, B. W., Tiburzi, C., Wucknitz, O., Wang, L., and Zhu, W. W.
Subjects: 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
Full Text: View/download PDF

36. Pulsars with NenuFAR: backend and pipelines

Author: Bondonneau, L., Grießmeier, J. -M., Theureau, G., Cognard, I., Brionne, M., Kondratiev, V., Bilous, A., McKee, J. W., Zarka, P., Viou, C., Guillemot, L., Chen, S., Main, R., Pilia, M., Possenti, A., Serylak, M., Shaifullah, G., Tiburzi, C., Verbiest, J. P. W., Wu, Z., Wucknitz, O., Yerin, S., Briand, C., Cecconi, B., Corbel, S., Dallier, R., Loh, A., Martin, L., Girard, J. N., and Tasse, C.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract: NenuFAR (New extension in Nan\c{c}ay upgrading LoFAR) is a new radio telescope developed and built on the site of the Nan\c{c}ay Radio Observatory. It is designed to observe the largely unexplored frequency window from 10 to 85\,MHz, offering a high sensitivity across its full bandwidth. NenuFAR has started its "early science" operation in July 2019, with 58\% of its final collecting area being available. Pulsars are one of the major topics for the scientific exploitation of this frequency range and represent an important challenge in terms of instrumentation. Designing instrumentation at these frequencies is complicated by the need to compensate for the effects of both the interstellar medium and the ionosphere on the observed signal. Our real-time pipeline LUPPI (Low frequency Ultimate Pulsar Processing Instrumentation) is able to cope with a high data rate and to provide real-time coherent de-dispersion down to the lowest frequencies reached by NenuFAR (10\,MHz). The full backend functionality is described, as well as the main pulsar observing modes (folded, single-pulse, waveform, and dynamic spectrum). This instrumentation allowed us to detect 172 pulsars in our first targeted search below 85\,MHz, including 10 millisecond pulsars (6 of which detected for the first time below 100 MHz). We also present some of the "early science" results of NenuFAR on pulsars: a high frequency resolution mapping of PSR B1919$+$21's emission profile and a detailed observation of single-pulse sub-structures from PSR~B0809$+$74 down to 16\,MHz, the high rate of giant-pulse emission from the Crab pulsar detected at 68.7\,MHz (43 events/min), and the illustration of the very good timing performance of the instrumentation, allowing us to study dispersion measure variations in great detail., Comment: 13 pages, 14 figures, submitted to A&A
Published: 2020
Full Text: View/download PDF

37. The CHIME Pulsar Project: System Overview

Author: Collaboration, CHIME/Pulsar, Amiri, M., Bandura, K. M., Boyle, P. J., Brar, C., Cliche, J. F., Crowter, K., Cubranic, D., Demorest, P. B., Denman, N. T., Dobbs, M., Dong, F. Q., Fandino, M., Fonseca, E., Good, D. C., Halpern, M., Hill, A. S., Höfer, C., Kaspi, V. M., Landecker, T. L., Leung, C., Lin, H. -H., Luo, J., Masui, K. W., McKee, J. W., Mena-Parra, J., Meyers, B. W., Michilli, D., Naidu, A., Newburgh, L., Ng, C., Patel, C., Pinsonneault-Marotte, T., Ransom, S. M., Renard, A., Scholz, P., Shaw, J. R., Sikora, A. E., Stairs, I. H., Tan, C. M., Tendulkar, S. P., Tretyakov, I., Vanderlinde, K., Wang, H., and Wang, X.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: We present the design, implementation and performance of a digital backend constructed for the Canadian Hydrogen Intensity Mapping Experiment (CHIME) that uses accelerated computing to observe radio pulsars and transient radio sources. When operating, the CHIME correlator outputs 10 independent streams of beamformed data for the CHIME/Pulsar backend that digitally track specified celestial positions. Each of these independent streams are processed by the CHIME/Pulsar backend system which can coherently dedisperse, in real-time, up to dispersion measure values of 2500 pc/cm$^{-3}$ . The tracking beams and real-time analysis system are autonomously controlled by a priority-based algorithm that schedules both known sources and positions of interest for observation with observing cadences as small as one day. Given the distribution of known pulsars and radio-transient sources, the CHIME/Pulsar system can monitor up to 900 positions once per sidereal day and observe all sources with declinations greater than $-20^\circ$ once every $\sim$2 weeks. We also discuss the science program enabled through the current modes of data acquisition for CHIME/Pulsar that centers on timing and searching experiments., Comment: 18 pages, 9 figures, 1 table. Submitted to ApJS
Published: 2020
Full Text: View/download PDF

38. A pulsar-based timescale from the International Pulsar Timing Array

Author: Hobbs, G., Guo, L., Caballero, R. N., Coles, W., Lee, K. J., Manchester, R. N., Reardon, D. J., Matsakis, D., Tong, M. L., Arzoumanian, Z., Bailes, M., Bassa, C. G., Bhat, N. D. R., Brazier, A., Burke-Spolaor, S., Champion, D. J., Chatterjee, S., Cognard, I., Dai, S., Desvignes, G., Dolch, T., Ferdman, R. D., Graikou, E., Guillemot, L., Janssen, G. H., Keith, M. J., Kerr, M., Kramer, M., Lam, M. T., Liu, K., Lyne, A., Lazio, T. J. W., Lynch, R., McKee, J. W., McLaughlin, M. A., Mingarelli, C. M. F., Nice, D. J., Oslowski, S., Pennucci, T. T., Perera, B. B. P., Perrodin, D., Possenti, A., Russell, C. J., Sanidas, S., Sesana, A., Shaifullah, G., Shannon, R. M., Simon, J., Spiewak, R., Stairs, I. H., Stappers, B. W., Swiggum, J. K., Taylor, S. R., Theureau, G., Toomey, L., van Haasteren, R., Wang, J. B., Wang, Y., and Zhu, X. J.
Subjects: Astrophysics - Instrumentation and Methods for Astrophysics
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: 2019
Full Text: View/download PDF

39. The International Pulsar Timing Array: Second data release

Author: Perera, B. B. P., DeCesar, M. E., Demorest, P. B., Kerr, M., Lentati, L., Nice, D. J., Oslowski, S., Ransom, S. M., Keith, M. J., Arzoumanian, Z., Bailes, M., Baker, P. T., Bassa, C. G., Bhat, N. D. R., Brazier, A., Burgay, M., Burke-Spolaor, S., Caballero, R. N., Champion, D. J., Chatterjee, S., Chen, S., Cognard, I., Cordes, J. M., Crowter, K., Dai, S., Desvignes, G., Dolch, T., Ferdman, R. D., Ferrara, E. C., Fonseca, E., Goldstein, J. M., Graikou, E., Guillemot, L., Hazboun, J. S., Hobbs, G., Hu, H., Islo, K., Janssen, G. H., Karuppusamy, R., Kramer, M., Lam, M. T., Lee, K. J., Liu, K., Luo, J., Lyne, A. G., Manchester, R. N., McKee, J. W., McLaughlin, M. A., Mingarelli, C. M. F., Parthasarathy, A. P., Pennucci, T. T., Perrodin, D., Possenti, A., Reardon, D. J., Russell, C. J., Sanidas, S. A., Sesana, A., Shaifullah, G., Shannon, R. M., Siemens, X., Simon, J., Spiewak, R., Stairs, I. H., Stappers, B. W., Swiggum, J. K., Taylor, S. R., Theureau, G., Tiburzi, C., Vallisneri, M., Vecchio, A., Wang, J. B., Zhang, S. B., Zhang, L., Zhu, W. W., and Zhu, X. J.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
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
Full Text: View/download PDF

40. The second data release from the European Pulsar Timing Array: IV. Implications for massive black holes, dark matter, and the early Universe

Author: Antoniadis, J, Arumugam, P, Arumugam, S, Babak, S, Bagchi, M, Bak Nielsen, A, Bassa, C, Bathula, A, Berthereau, A, Bonetti, M, Bortolas, E, Brook, P, Burgay, M, Caballero, R, Chalumeau, A, Champion, D, Chanlaridis, S, Chen, S, Cognard, I, Dandapat, S, Deb, D, Desai, S, Desvignes, G, Dhanda-Batra, N, Dwivedi, C, Falxa, M, Ferdman, R, Franchini, A, Gair, J, Goncharov, B, Gopakumar, A, Graikou, E, Grießmeier, J, Gualandris, A, Guillemot, L, Guo, Y, Gupta, Y, Hisano, S, Hu, H, Iraci, F, Izquierdo Villalba, D, Jang, J, Jawor, J, Janssen, G, Jessner, A, Joshi, B, Kareem, F, Karuppusamy, R, Keane, E, Keith, M, Kharbanda, D, Kikunaga, T, Kolhe, N, Kramer, M, Krishnakumar, M, Lackeos, K, Lee, K, Liu, K, Liu, Y, Lyne, A, Mckee, J, Maan, Y, Main, R, Mickaliger, M, Niţu, I, Nobleson, K, Paladi, A, Parthasarathy, A, Perera, B, Perrodin, D, Petiteau, A, Porayko, N, Possenti, A, Prabu, T, Quelquejay Leclere, H, Rana, P, Samajdar, A, Sanidas, S, Sesana, A, Shaifullah, G, Singha, J, Speri, L, Spiewak, R, Srivastava, A, Stappers, B, Surnis, M, Susarla, S, Susobhanan, A, Takahashi, K, Tarafdar, P, Theureau, G, Tiburzi, C, Van Der Wateren, E, Vecchio, A, Venkatraman Krishnan, V, Verbiest, J, Wang, J, Wang, L, Wu, Z, Auclair, P, Antoniadis J., Arumugam P., Arumugam S., Babak S., Bagchi M., Bak Nielsen A. S., Bassa C. G., Bathula A., Berthereau A., Bonetti M., Bortolas E., Brook P. R., Burgay M., Caballero R. N., Chalumeau A., Champion D. J., Chanlaridis S., Chen S., Cognard I., Dandapat S., Deb D., Desai S., Desvignes G., Dhanda-Batra N., Dwivedi C., Falxa M., Ferdman R. D., Franchini A., Gair J. R., Goncharov B., Gopakumar A., Graikou E., Grießmeier J. M., Gualandris A., Guillemot L., Guo Y. J., Gupta Y., Hisano S., Hu H., Iraci F., Izquierdo Villalba D., Jang J., Jawor J., Janssen G. H., Jessner A., Joshi B. C., Kareem F., Karuppusamy R., Keane E. F., Keith M. J., Kharbanda D., Kikunaga T., Kolhe N., Kramer M., Krishnakumar M. A., Lackeos K., Lee K. J., Liu K., Liu Y., Lyne A. G., McKee J. W., Maan Y., Main R. A., Mickaliger M. B., Niţu I. C., Nobleson K., Paladi A. K., Parthasarathy A., Perera B. B. P., Perrodin D., Petiteau A., Porayko N. K., Possenti A., Prabu T., Quelquejay Leclere H., Rana P., Samajdar A., Sanidas S. A., Sesana A., Shaifullah G., Singha J., Speri L., Spiewak R., Srivastava A., Stappers B. W., Surnis M., Susarla S. C., Susobhanan A., Takahashi K., Tarafdar P., Theureau G., Tiburzi C., Van Der Wateren E., Vecchio A., Venkatraman Krishnan V., Verbiest J. P. W., Wang J., Wang L., Wu Z., Auclair P., Antoniadis, J, Arumugam, P, Arumugam, S, Babak, S, Bagchi, M, Bak Nielsen, A, Bassa, C, Bathula, A, Berthereau, A, Bonetti, M, Bortolas, E, Brook, P, Burgay, M, Caballero, R, Chalumeau, A, Champion, D, Chanlaridis, S, Chen, S, Cognard, I, Dandapat, S, Deb, D, Desai, S, Desvignes, G, Dhanda-Batra, N, Dwivedi, C, Falxa, M, Ferdman, R, Franchini, A, Gair, J, Goncharov, B, Gopakumar, A, Graikou, E, Grießmeier, J, Gualandris, A, Guillemot, L, Guo, Y, Gupta, Y, Hisano, S, Hu, H, Iraci, F, Izquierdo Villalba, D, Jang, J, Jawor, J, Janssen, G, Jessner, A, Joshi, B, Kareem, F, Karuppusamy, R, Keane, E, Keith, M, Kharbanda, D, Kikunaga, T, Kolhe, N, Kramer, M, Krishnakumar, M, Lackeos, K, Lee, K, Liu, K, Liu, Y, Lyne, A, Mckee, J, Maan, Y, Main, R, Mickaliger, M, Niţu, I, Nobleson, K, Paladi, A, Parthasarathy, A, Perera, B, Perrodin, D, Petiteau, A, Porayko, N, Possenti, A, Prabu, T, Quelquejay Leclere, H, Rana, P, Samajdar, A, Sanidas, S, Sesana, A, Shaifullah, G, Singha, J, Speri, L, Spiewak, R, Srivastava, A, Stappers, B, Surnis, M, Susarla, S, Susobhanan, A, Takahashi, K, Tarafdar, P, Theureau, G, Tiburzi, C, Van Der Wateren, E, Vecchio, A, Venkatraman Krishnan, V, Verbiest, J, Wang, J, Wang, L, Wu, Z, Auclair, P, Antoniadis J., Arumugam P., Arumugam S., Babak S., Bagchi M., Bak Nielsen A. S., Bassa C. G., Bathula A., Berthereau A., Bonetti M., Bortolas E., Brook P. R., Burgay M., Caballero R. N., Chalumeau A., Champion D. J., Chanlaridis S., Chen S., Cognard I., Dandapat S., Deb D., Desai S., Desvignes G., Dhanda-Batra N., Dwivedi C., Falxa M., Ferdman R. D., Franchini A., Gair J. R., Goncharov B., Gopakumar A., Graikou E., Grießmeier J. M., Gualandris A., Guillemot L., Guo Y. J., Gupta Y., Hisano S., Hu H., Iraci F., Izquierdo Villalba D., Jang J., Jawor J., Janssen G. H., Jessner A., Joshi B. C., Kareem F., Karuppusamy R., Keane E. F., Keith M. J., Kharbanda D., Kikunaga T., Kolhe N., Kramer M., Krishnakumar M. A., Lackeos K., Lee K. J., Liu K., Liu Y., Lyne A. G., McKee J. W., Maan Y., Main R. A., Mickaliger M. B., Niţu I. C., Nobleson K., Paladi A. K., Parthasarathy A., Perera B. B. P., Perrodin D., Petiteau A., Porayko N. K., Possenti A., Prabu T., Quelquejay Leclere H., Rana P., Samajdar A., Sanidas S. A., Sesana A., Shaifullah G., Singha J., Speri L., Spiewak R., Srivastava A., Stappers B. W., Surnis M., Susarla S. C., Susobhanan A., Takahashi K., Tarafdar P., Theureau G., Tiburzi C., Van Der Wateren E., Vecchio A., Venkatraman Krishnan V., Verbiest J. P. W., Wang J., Wang L., Wu Z., and Auclair P.
Abstract: The European Pulsar Timing Array (EPTA) and Indian Pulsar Timing Array (InPTA) collaborations have measured a low-frequency common signal in the combination of their second and first data releases, respectively, with the correlation properties of a gravitational wave background (GWB). Such a signal may have its origin in a number of physical processes including a cosmic population of inspiralling supermassive black hole binaries (SMBHBs); inflation, phase transitions, cosmic strings, and tensor mode generation by the non-linear evolution of scalar perturbations in the early Universe; and oscillations of the Galactic potential in the presence of ultra-light dark matter (ULDM). At the current stage of emerging evidence, it is impossible to discriminate among the different origins. Therefore, for this paper, we consider each process separately, and investigated the implications of the signal under the hypothesis that it is generated by that specific process. We find that the signal is consistent with a cosmic population of inspiralling SMBHBs, and its relatively high amplitude can be used to place constraints on binary merger timescales and the SMBH-host galaxy scaling relations. If this origin is confirmed, this would be the first direct evidence that SMBHBs merge in nature, adding an important observational piece to the puzzle of structure formation and galaxy evolution. As for early Universe processes, the measurement would place tight constraints on the cosmic string tension and on the level of turbulence developed by first-order phase transitions. Other processes would require non-standard scenarios, such as a blue-tilted inflationary spectrum or an excess in the primordial spectrum of scalar perturbations at large wavenumbers. Finally, a ULDM origin of the detected signal is disfavoured, which leads to direct constraints on the abundance of ULDM in our Galaxy.
Published: 2024

41. Modeling nonstationary noise in pulsar timing array data analysis

Author: Falxa, Mikel, primary, Antoniadis, J., additional, Champion, D. J., additional, Cognard, I., additional, Desvignes, G., additional, Guillemot, L., additional, Hu, H., additional, Janssen, G., additional, Jawor, J., additional, Karuppusamy, R., additional, Keith, M. J., additional, Kramer, M., additional, Lackeos, K., additional, Liu, K., additional, McKee, J. W., additional, Perrodin, D., additional, Sanidas, S. A., additional, Shaifullah, G. M., additional, and Theureau, G., additional
Published: 2024
Full Text: View/download PDF

42. A detailed study of giant pulses from PSR B1937+21 using the Large European Array for Pulsars

Author: McKee, J. W., Stappers, B. W., Bassa, C. G., Chen, S., Cognard, I., Gaikwad, M., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., Liu, K., Perrodin, D., Sanidas, S. A., Smits, R., Wang, L., and Zhu, W. W.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
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: 2018
Full Text: View/download PDF

43. Studying the solar system with the International Pulsar Timing Array

Author: Caballero, R. N., Guo, Y. J., Lee, K. J., Lazarus, P., Champion, D. J., Desvignes, G., Kramer, M., Plant, K., Arzoumanian, Z., Bailes, M., Bassa, C. G., Bhat, N. D. R., Brazier, A., Burgay, M., Burke-Spolaor, S., Chamberlin, S. J., Chatterjee, S., Cognard, I., Cordes, J. M., Dai, S., Demorest, P., Dolch, T., Ferdman, R. D., Fonseca, E., Gair, J. R., Garver-Daniels, N., Gentile, P., Gonzalez, M. E., Graikou, E., Guillemot, L., Hobbs, G., Janssen, G. H., Karuppusamy, R., Keith, M. J., Kerr, M., Lam, M. T., Lasky, P. D., Lazio, T. J. W., Levin, L., Liu, K., Lommen, A. N., Lorimer, D. R., Lynch, R. S., Madison, D. R., Manchester, R. N., McKee, J. W., McLaughlin, M. A., McWilliams, S. T., Mingarelli, C. M. F., Nice, D. J., Osłowski, S., Palliyaguru, N. T., Pennucci, T. T., Perera, B. B. P., Perrodin, D., Possenti, A., Ransom, S. M., Reardon, D. J., Sanidas, S. A., Sesana, A., Shaifullah, G., Shannon, R. M., Siemens, X., Simon, J., Spiewak, R., Stairs, I., Stappers, B., Stinebring, D. R., Stovall, K., Swiggum, J. K., Taylor, S. R., Theureau, G., Tiburzi, C., Toomey, L., van Haasteren, R., van Straten, W., Verbiest, J. P. W., Wang, J. B., Zhu, X. J., and Zhu, W. W.
Subjects: 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
Full Text: View/download PDF

44. Temporal variations in scattering and dispersion measure in the Crab Pulsar and their effect on timing precision

Author: McKee, J. W., Lyne, A. G., Stappers, B. W., Bassa, C. G., and Jordan, C. A.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
Abstract: We have measured variations in scattering time scales in the Crab Pulsar over a 30-year period, using observations made at 610 MHz with the 42-ft telescope at Jodrell Bank Observatory. Over more recent years, where regular Lovell Telescope observations at frequencies around 1400 MHz were available, we have also determined the dispersion measure variations, after disentangling the scattering delay from the dispersive delay. We demonstrate a relationship between scattering and dispersion measure variations, with a correlation coefficient of $0.56\pm0.01$. The short time scales over which these quantities vary, the size of the variations, and the close correlation between scattering and dispersion measure all suggest that the effects are due to discrete structures within the Crab Nebula, with size scales of $\sim6$ AU (corresponding to an angular size of $\sim2$ mas at an assumed distance of 2200 pc). We mitigate the effects of scattering on the observed pulse shape by using the measured scattering information to modify the template used for generating the pulse arrival times, thus improving the precision to which the pulsar can be timed. We test this on timing data taken during periods of high scattering, and obtain a factor of two improvement in the root mean square of the timing residuals., Comment: 10 pages, 7 figures. Accepted for publication in MNRAS
Published: 2018
Full Text: View/download PDF

45. Improving timing sensitivity in the microhertz frequency regime: limits from PSR J1713$+$0747 on gravitational waves produced by super-massive black-hole binaries

Author: Perera, B. B. P., Stappers, B. W., Babak, S., Keith, M. J., Antoniadis, J., Bassa, C. G., Caballero, R. N., Champion, D. J., Cognard, I., Desvignes, G., Graikou, E., Guillemot, L., Janssen, G. H., Karuppusamy, R., Kramer, M., Lazarus, P., Lentati, L., Liu, K., Lyne, A. G., McKee, J. W., Oslowski, S., Perrodin, D., Sanidas, S. A., Sesana, A., Shaifullah, G., Theureau, G., Verbiest, J. P. W., and Taylor, S. R.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
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
Full Text: View/download PDF

46. Tests of Gravitational Symmetries with Pulsar Binary J1713+0747

Author: Zhu, W. W., Desvignes, G., Wex, N., Caballero, R. N., Champion, D. J., Demorest, P. B., Ellis, J. A., Janssen, G. H., Kramer, M., Krieger, A., Lentati, L., Nice, D. J., Ransom, S. M., Stairs, I. H., Stappers, B. W., Verbiest, J. P. W., Arzoumanian, Z., Bassa, C. G., Burgay, M., Cognard, I., Crowter, K., Dolch, T., Ferdman, R. D., Fonseca, E., Gonzalez, M. E., Graikou, E., Guillemot, L., Hessels, J. W. T., Jessner, A., Jones, G., Jones, M. L., Jordan, C., Karuppusamy, R., Lam, M. T., Lazaridis, K., Lazarus, P., Lee, K. J., Levin, L., Liu, K., Lyne, A. G., McKee, J. W., McLaughlin, M. A., Osłowski, S., Pennucci, T., Perrodin, D., Possenti, A., Sanidas, S., Shaifullah, G., Smits, R., Stovall, K., Swiggum, J., Theureau, G., and Tiburzi, C.
Subjects: Astrophysics - High Energy Astrophysical Phenomena
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: 2018
Full Text: View/download PDF

47. Pulsar science with data from the Large European Array for Pulsars

Author: McKee, J. W., Bassa, C. G., Chen, S., Gaikwad, M., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., Liu, K., Perrodin, D., Sanidas, S. A., Smits, R., Stappers, B. W., Wang, L., and Zhu, W. W.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Instrumentation and Methods for Astrophysics
Abstract: The Large European Array for Pulsars (LEAP) is a European Pulsar Timing Array project that combines the Lovell, Effelsberg, Nan\c{c}ay, Sardinia, and Westerbork radio telescopes into a single tied-array, and makes monthly observations of a set of millisecond pulsars (MSPs). The overview of our experiment is presented in Bassa et al. (2016). Baseband data are recorded at a central frequency of 1396 MHz and a bandwidth of 128 MHz at each telescope, and are correlated offline on a cluster at Jodrell Bank Observatory using a purpose-built correlator, detailed in Smits et al. (2017). LEAP offers a substantial increase in sensitivity over that of the individual telescopes, and can operate in timing and imaging modes (notably in observations of the galactic centre radio magnetar; Wucknitz 2015). To date, 4 years of observations have been reduced. Here, we report on the scientific projects which have made use of LEAP data., Comment: 2 pages, 1 figure, accepted for publication in the proceedings of IAU Symposium 337 - Pulsar Astrophysics: The Next Fifty Years
Published: 2017
Full Text: View/download PDF

48. Activation of Microwave Fields in a Spin-Torque Nano-Oscillator by Neuronal Action Potentials

Author: Algarin, J. M., Ramaswamy, B., Venuti, L., Swierzbinski, M. E., Baker-McKee, J., Weinberg, I. N., Chen, Y. J., Krivorotov, I. N., Katine, J. A., Herberholz, J., Araneda, R. C., Shapiro, B., and Waks, E.
Subjects: Physics - Applied Physics
Abstract: Action potentials are the basic unit of information in the nervous system and their reliable detection and decoding holds the key to understanding how the brain generates complex thought and behavior. Transducing these signals into microwave field oscillations can enable wireless sensors that report on brain activity through magnetic induction. In the present work we demonstrate that action potentials from crayfish lateral giant neuron can trigger microwave oscillations in spin-torque nano-oscillators. These nanoscale devices take as input small currents and convert them to microwave current oscillations that can wirelessly broadcast neuronal activity, opening up the possibility for compact neuro-sensors. We show that action potentials activate microwave oscillations in spin-torque nano-oscillators with an amplitude that follows the action potential signal, demonstrating that the device has both the sensitivity and temporal resolution to respond to action potentials from a single neuron. The activation of magnetic oscillations by action potentials, together with the small footprint and the high frequency tunability, makes these devices promising candidates for high resolution sensing of bioelectric signals from neural tissues. These device attributes may be useful for design of high-throughput bi-directional brain-machine interfaces.
Published: 2017

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

Author: Smits, R., Bassa, C. G., Janssen, G. H., Karuppusamy, R., Kramer, M., Lee, K. J., Liu, K., McKee, J., Perrodin, D., Purver, M., Sanidas, S., Stappers, B. W., and Zhu, W. W.
Subjects: 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

50. Variability, polarimetry, and timing properties of single pulses from PSR J1713+0747 using the Large European Array for Pulsars

Author: Liu, K., Bassa, C. G., Janssen, G. H., Karuppusamy, R., McKee, J., Kramer, M., Lee, K. J., Perrodin, D., Purver, M., Sanidas, S., Smits, R., Stappers, B. W., Weltevrede, P., and Zhu, W. W.
Subjects: Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Astrophysics of Galaxies
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., Comment: 11 pages, 14 figures, 2 tables, accepted for publication in MNRAS
Published: 2016
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Topic

Publication Year Range

Language

Publication Type

Journal

Region

Database

Publisher

1,590 results on '"Mckee, J"'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources