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1. NGC 4051: Black hole mass and photon index-mass accretion rate correlation

Author

Seifina, Elena, Chekhtman, Alexandre, and Titarchuk, Lev

Subjects
Astrophysics - Astrophysics of Galaxies, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present a discovery of the correlation between the X-ray spectral (photon) index and mass accretion rate observed in AGN NGC 4051. We analyzed spectral transition episodes observed in NGC 4051 using XMM/Newton, Suzaku and RXTE. We applied a scaling technique for a black hole (BH) mass evaluation which uses a correlation between the photon index and normalization of the seed (disk) component, which is proportional to a mass accretion rate. We developed an analytical model that shows the spectral (photon) index of the BH emergent spectrum undergoes an evolution from lower to higher values depending on a mass accretion rate in the accretion disk. We considered Cygnus X-1 and GRO~J1550-564 as reference sources for which distances, inclination angles and the BH masses are evaluated by dynamical measurements. Application of the scaling technique for the photon index-mass accretion rate correlation provides an estimate of the black hole mass in NGC 4051 to be more than 6x10^5 solar masses., Comment: 11 pages, 6 Figures and 8 Tables. arXiv admin note: text overlap with arXiv:0902.2852

Published
2018
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3. Einstein@Home discovers a radio-quiet gamma-ray millisecond pulsar

Author

Clark, Colin J., Pletsch, Holger J., Aulbert, Carsten, Orienti, Monica, Orlando, Elena, Palatiello, Michele, Paliya, Vaidehi S., de Palma, Francesco, Paneque, David, Perkins, Jeremy S., Persic, Massimo, Pesce-Rollins, Melissa, Porter, Troy A., Beer, Christian, Principe, Giacomo, Rainò, Silvia, Rando, Riccardo, Ray, Paul S., Razzano, Massimiliano, Reimer, Anita, Reimer, Olaf, Romani, Roger W., Saz Parkinson, Pablo M., Sgrò, Carmelo, Bock, Oliver, Siskind, Eric J., Smith, David A., Spada, Francesca, Spandre, Gloria, Spinelli, Paolo, Thayer, Jana B., Thompson, David J., Torres, Diego F., Troja, Eleonora, Vianello, Giacomo, Cuéllar, Andres, Wood, Kent, Wood, Matthew, Fermi-LAT Collaboration, Eggenstein, Heinz-Bernd, Fehrmann, Henning, Kramer, Michael, Kwang, Shawn A., Machenschalk, Bernd, Nieder, Lars, Wu, Jason, Ackermann, Markus, Ajello, Marco, Baldini, Luca, Ballet, Jean, Barbiellini, Guido, Bastieri, Denis, Bellazzini, Ronaldo, Bissaldi, Elisabetta, Blandford, Roger D., Bloom, Elliott D., Guillemot, Lucas, Bonino, Raffaella, Bottacini, Eugenio, Brandt, Terri J., Bregeon, Johan, Bruel, Philippe, Buehler, Rolf, Burnett, Toby H., Buson, Sara, Cameron, Rob A., Caputo, Regina, Kerr, Matthew, Caraveo, Patrizia A., Cavazzuti, Elisabetta, Cecchi, Claudia, Charles, Eric, Chekhtman, Alexandre, Ciprini, Stefano, Cominsky, Lynn R., Costantin, Denise, Cutini, Sara, D'Ammando, Filippo, Johnson, Tyrel J., De Luca, Andrea, Desiante, Rachele, Di Venere, Leonardo, Di Mauro, Mattia, Di Lalla, Niccolò, Digel, Seth W., Favuzzi, Cecilia, Ferrara, Elizabeth C., Franckowiak, Anna, Fukazawa, Yasushi, Camilo, Fernando, Funk, Stefan, Fusco, Piergiorgio, Gargano, Fabio, Gasparrini, Dario, Giglietto, Nico, Giordano, Francesco, Giroletti, Marcello, Gomez-Vargas, Germán A., Green, David, Grenier, Isabelle A., Salvetti, David, Guiriec, Sylvain, Harding, Alice K., Hewitt, John W., Horan, Deirdre, Jóhannesson, Guðlaugur, Kensei, Shiki, Kuss, Michael, La Mura, Giovanni, Larsson, Stefan, Latronico, Luca, Allen, Bruce, Li, Jian, Longo, Francesco, Loparco, Francesco, Lovellette, Michael N., Lubrano, Pasquale, Magill, Jeffrey D., Maldera, Simone, Manfreda, Alberto, Mazziotta, Mario N., McEnery, Julie E., Anderson, David, Michelson, Peter F., Mirabal, Nestor, Mitthumsiri, Warit, Mizuno, Tsunefumi, Monzani, Maria Elena, Morselli, Aldo, Moskalenko, Igor V., Nuss, Eric, Ohsugi, Takashi, Omodei, Nicola, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Unité Scientifique de la Station de Nançay (USN), Université d'Orléans (UO)-Observatoire des Sciences de l'Univers en région Centre (OSUC), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Univers et Particules de Montpellier (LUPM), Université de Montpellier (UM)-Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Leprince-Ringuet (LLR), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Centre d'Etudes Nucléaires de Bordeaux Gradignan (CENBG), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Fermi-LAT, Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), ITA, Centre National de la Recherche Scientifique (CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers en région Centre (OSUC), Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Centre National de la Recherche Scientifique ( CNRS ) -Université d'Orléans ( UO ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Unité Scientifique de la Station de Nançay ( USN ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire AIM, Université Paris Diderot - Paris 7 ( UPD7 ) -Centre d'Etudes de Saclay, Laboratoire Univers et Particules de Montpellier ( LUPM ), Centre National de la Recherche Scientifique ( CNRS ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Université Montpellier 2 - Sciences et Techniques ( UM2 ) -Université de Montpellier ( UM ), Laboratoire Leprince-Ringuet ( LLR ), Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -École polytechnique ( X ) -Centre National de la Recherche Scientifique ( CNRS ), Centre d'Etudes Nucléaires de Bordeaux Gradignan ( CENBG ), Université Sciences et Technologies - Bordeaux 1-Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Raunvísindastofnun (HÍ), Science Institute (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland, Clark, Colin J., Pletsch, Holger J., Wu, Jason, Guillemot, Luca, Kerr, Matthew, Johnson, Tyrel J., Camilo, Fernando, Salvetti, David, Allen, Bruce, Anderson, David, Aulbert, Carsten, Beer, Christian, Bock, Oliver, Cuéllar, Andre, Eggenstein, Heinz-Bernd, Fehrmann, Henning, Kramer, Michael, Kwang, Shawn A., Machenschalk, Bernd, Nieder, Lar, Ackermann, Marku, Ajello, Marco, Baldini, Luca, Ballet, Jean, Barbiellini, Guido, Bastieri, Deni, Bellazzini, Ronaldo, Bissaldi, Elisabetta, Blandford, Roger D., Bloom, Elliott D., Bonino, Raffaella, Bottacini, Eugenio, Brandt, Terri J., Bregeon, Johan, Bruel, Philippe, Buehler, Rolf, Burnett, Toby H., Buson, Sara, Cameron, Rob A., Caputo, Regina, Caraveo, Patrizia A., Cavazzuti, Elisabetta, Cecchi, Claudia, Charles, Eric, Chekhtman, Alexandre, Ciprini, Stefano, Cominsky, Lynn R., Costantin, Denise, Cutini, Sara, D'Ammando, Filippo, De Luca, Andrea, Desiante, Rachele, Di Venere, Leonardo, Di Mauro, Mattia, Di Lalla, Niccolò, Digel, Seth W., Favuzzi, Cecilia, Ferrara, Elizabeth C., Franckowiak, Anna, Fukazawa, Yasushi, Funk, Stefan, Fusco, Piergiorgio, Gargano, Fabio, Gasparrini, Dario, Giglietto, Nico, Giordano, Francesco, Giroletti, Marcello, Gomez-Vargas, Germán A., Green, David, Grenier, Isabelle A., Guiriec, Sylvain, Harding, Alice K., Hewitt, John W., Horan, Deirdre, Jóhannesson, Guolaugur, Kensei, Shiki, Kuss, Michael, La Mura, Giovanni, Larsson, Stefan, Latronico, Luca, Li, Jian, Longo, Francesco, Loparco, Francesco, Lovellette, Michael N., Lubrano, Pasquale, Magill, Jeffrey D., Maldera, Simone, Manfreda, Alberto, Mazziotta, Mario N., Mcenery, Julie E., Michelson, Peter F., Mirabal, Nestor, Mitthumsiri, Warit, Mizuno, Tsunefumi, Monzani, Maria Elena, Morselli, Aldo, Moskalenko, Igor V., Nuss, Eric, Ohsugi, Takashi, Omodei, Nicola, Orienti, Monica, Orlando, Elena, Palatiello, Michele, Paliya, Vaidehi S., De Palma, Francesco, Paneque, David, Perkins, Jeremy S., Persic, Massimo, Pesce-Rollins, Melissa, Porter, Troy A., Principe, Giacomo, Rainò, Silvia, Rando, Riccardo, Ray, Paul S., Razzano, Massimiliano, Reimer, Anita, Reimer, Olaf, Romani, Roger W., Parkinson, Pablo M. Saz, Sgrò, Carmelo, Siskind, Eric J., Smith, David A., Spada, Francesca, Spandre, Gloria, Spinelli, Paolo, Thayer, Jana B., Thompson, David J., Torres, Diego F., Troja, Eleonora, Vianello, Giacomo, Wood, Kent, and Wood, Matthew

Subjects
Einstein@Home, Gammageislar, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Astronomy, Astrophysics::High Energy Astrophysical Phenomena, Population, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, law.invention, Telescope, Computer Science::Hardware Architecture, Bulge, Millisecond pulsar, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010306 general physics, education, 010303 astronomy & astrophysics, Research Articles, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), education.field_of_study, Line-of-sight, Multidisciplinary, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Nifteindastjörnur, Astrophysics::Instrumentation and Methods for Astrophysics, SciAdv r-articles, Computer Science::Computers and Society, Stjörnusjónaukar, Neutron star, ddc:500, Astrophysics - High Energy Astrophysical Phenomena, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Fermi Gamma-ray Space Telescope, Research Article
Abstract

Millisecond pulsars (MSPs) are old neutron stars that spin hundreds of times per second and appear to pulsate as their emission beams cross our line of sight. To date, radio pulsations have been detected from all rotation-powered MSPs. In an attempt to discover radio-quiet gamma-ray MSPs, we used the aggregated power from the computers of tens of thousands of volunteers participating in the Einstein@Home distributed computing project to search for pulsations from unidentified gamma-ray sources in Fermi Large Area Telescope data. This survey discovered two isolated MSPs, one of which is the only known rotation-powered MSP to remain undetected in radio observations. These gamma-ray MSPs were discovered in completely blind searches without prior constraints from other observations, raising hopes for detecting MSPs from a predicted Galactic bulge population., This work was supported by the Max-Planck-Gesellschaft, the Deutsche Forschungsgemeinschaft through an Emmy Noether Research Grant [no. PL 710/1-1 (H.J.P.)], and NSF award 1104902. C.J.C. acknowledges support from the European Research Council under the European Union’s Horizon 2020 research and innovation programme (grant agreement no. 715051; Spiders). W.M. was partially supported by the Thailand Research Fund (grants TRG5880173 and RTA5980003). M.R. was funded by the Italian Ministry of Education, University and Research (contract no. FIRB-2012-RBFR12PM1F). Work at the Naval Research Laboratory is supported by NASA. The Parkes Observatory is part of the Australia Telescope, funded by the Commonwealth of Australia for operation as a National Facility managed by the Commonwealth Scientific and Industrial Research Organisation (CSIRO). The Fermi LAT Collaboration acknowledges generous ongoing support from a number of agencies and institutes that have supported both the development and the operation of the LAT, as well as scientific data analysis. These include the National Aeronautics and Space Administration and the Department of Energy in the United States, the Commissariat à l’Energie Atomique and the Centre National de la Recherche Scientifique/Institut National de Physique Nucléaire et de Physique des Particules in France; the Agenzia Spaziale Italiana and the Istituto Nazionale di Fisica Nucleare in Italy, the Ministry of Education, Culture, Sports, Science and Technology (MEXT), High Energy Accelerator Research Organization (KEK), and Japan Aerospace Exploration Agency (JAXA) in Japan; and the K. A. Wallenberg Foundation, the Swedish Research Council, and the Swedish National Space Board in Sweden. Additional support for science analysis during the operations phase is gratefully acknowledged from the Istituto Nazionale di Astrofisica in Italy and the Centre National d’Études Spatiales in France. This work performed in part under DOE Contract DE-AC02-76SF00515.

Published
2018

5. A population of gamma-ray emitting globular clusters seen with the Fermi Large Area Telescope

Author

Abdo, Aous A., Ackermann, Markus, Ajello, Marco, Baldini, Luca, Ballet, Jean, Barbiellini, Guido, Bastieri, Denis, Bellazzini, Ronaldo, Blandford, Roger D., Bloom, Elliott D., Bonamente, Emanuele, Ormes, Jonathan F., Reimer, Anita, Reimer, Olaf, Reposeur, Thierry, Borgland, Anders W., Ripken, Joachim, Romani, Roger W., Ziegler, Marcus, Roth, Marshall, Sadrozinski, Hartmut F. W., Ylinen, Tomi, Saz Parkinson, Pablo M., Sgrò, Carmelo, Siskind, Eric J., Smith, David A., Spinelli, Paolo, Strickman, Mark Samuel, Bouvier, Aurelien, Suson, Daniel Jeffrey, Brigida, Monica, Takahashi, Hiromitsu, Buson, Sara, Takahashi, Tadayuki, Tanaka, Takaaki, Thayer, Jana B., Thayer, John Gregg, Tibaldo, Luigi, Torres, Diego F., Tosti, Gino, Tramacere, Andrea, Brandt, Theresa J., Bruel, Philippe, Caliandro, Giuseppe Andrea, Uchiyama, Yasunobu, Usher, Tracy L., Vasileiou, Vlasios, Venter, Christo, Vilchez, Nicolás, Vitale, Vincenzo, Waite, Anthony P., Wang, Ping, Webb, Natalie, Winer, Brian L., Cameron, Robert A., Buehler, Rolf, Bregeon, Jean, Yang, Zhaoyu, Caraveo, Patrizia A., Carrigan, Svenja, Casandjian, Jean-Marc, Guillemot, Lucas, Charles, Eric, Chaty, Sylvain, Grove, J. Eric, Chekhtman, Alexandre, Cheung, C. C. Teddy, Chiang, James, Ciprini, Stefano, Claus, Rachel, Cohen-Tanugi, Johan, Conrad, Jan, DeCesar, Megan E., Guiriec, Sylvain, Dermer, Charles Dennison, Hays, Elizabeth, Palma, Francesco de, Digel, Seth W., Couto e Silva, Eduardo do, Drell, Persis S., Dubois, Richard, Dumora, Denis, Favuzzi, Cecilia, Fortin, Pascal, Frailis, Marco, Hadasch, Daniela, Jean, Pierre, Fukazawa, Yasushi, Fusco, Piergiorgio, Gargano, Fabio, Gasparrini, Dario, Gehrels, Neil, Germani, Stefano, Giglietto, Nicola, Giordano, Francesco, Glanzman, Tom, Godfrey, Gary, Johannesson, Gueolaugur, Harding, Alice K., Grenier, Isabelle A., Grondin, Marie-Hélène, Johnson, Tyrel J., Johnson, W. Neil, Kamae, Tuneyoshi, Parent, D., Katagiri, Hideaki, Kataoka, Jun, Pancrazi, Benoit, Kerr, Matthew, Knödlseder, Jürgen, Kuss, M., Lande, Joshua, Latronico, Luca, Lee, Shiu-Hang, Lemoine-Goumard, Marianne, Llena-Garde, Maja, Pepe, Monica, Longo, Francesco, Porter, Troy A., Loparco, Francesco, Lovellette, Michael N., Lubrano, Pasquale, Makeev, Andrey, Mazziotta, Mario Nicola, Michelson, Peter F., Mitthumsiri, Warit, Mizuno, Takafumi, Monte, Claudia, Pesce-Rollins, Melissa, Rainò, Silvia, Monzani, Maria Elena, Morselli, Aldo, Moskalenko, Igor V., Murgia, Simona, Naumann-Godo, Melitta, Nolan, Pat L., Norris, Jay P., Nuss, Eric, Ohsugi, Takashi, Omodei, Nicola, Rando, Riccardo, Piron, Frédéric, Orlando, Elena, Abdo, Aous A., Ackermann, Markus, Ajello, Marco, Baldini, Luca, Ballet, Jean, Barbiellini, Guido, Bastieri, Denis, Bellazzini, Ronaldo, Blandford, Roger D., Bloom, Elliott D., Bonamente, Emanuele, Ormes, Jonathan F., Reimer, Anita, Reimer, Olaf, Reposeur, Thierry, Borgland, Anders W., Ripken, Joachim, Romani, Roger W., Ziegler, Marcus, Roth, Marshall, Sadrozinski, Hartmut F. W., Ylinen, Tomi, Saz Parkinson, Pablo M., Sgrò, Carmelo, Siskind, Eric J., Smith, David A., Spinelli, Paolo, Strickman, Mark Samuel, Bouvier, Aurelien, Suson, Daniel Jeffrey, Brigida, Monica, Takahashi, Hiromitsu, Buson, Sara, Takahashi, Tadayuki, Tanaka, Takaaki, Thayer, Jana B., Thayer, John Gregg, Tibaldo, Luigi, Torres, Diego F., Tosti, Gino, Tramacere, Andrea, Brandt, Theresa J., Bruel, Philippe, Caliandro, Giuseppe Andrea, Uchiyama, Yasunobu, Usher, Tracy L., Vasileiou, Vlasios, Venter, Christo, Vilchez, Nicolás, Vitale, Vincenzo, Waite, Anthony P., Wang, Ping, Webb, Natalie, Winer, Brian L., Cameron, Robert A., Buehler, Rolf, Bregeon, Jean, Yang, Zhaoyu, Caraveo, Patrizia A., Carrigan, Svenja, Casandjian, Jean-Marc, Guillemot, Lucas, Charles, Eric, Chaty, Sylvain, Grove, J. Eric, Chekhtman, Alexandre, Cheung, C. C. Teddy, Chiang, James, Ciprini, Stefano, Claus, Rachel, Cohen-Tanugi, Johan, Conrad, Jan, DeCesar, Megan E., Guiriec, Sylvain, Dermer, Charles Dennison, Hays, Elizabeth, Palma, Francesco de, Digel, Seth W., Couto e Silva, Eduardo do, Drell, Persis S., Dubois, Richard, Dumora, Denis, Favuzzi, Cecilia, Fortin, Pascal, Frailis, Marco, Hadasch, Daniela, Jean, Pierre, Fukazawa, Yasushi, Fusco, Piergiorgio, Gargano, Fabio, Gasparrini, Dario, Gehrels, Neil, Germani, Stefano, Giglietto, Nicola, Giordano, Francesco, Glanzman, Tom, Godfrey, Gary, Johannesson, Gueolaugur, Harding, Alice K., Grenier, Isabelle A., Grondin, Marie-Hélène, Johnson, Tyrel J., Johnson, W. Neil, Kamae, Tuneyoshi, Parent, D., Katagiri, Hideaki, Kataoka, Jun, Pancrazi, Benoit, Kerr, Matthew, Knödlseder, Jürgen, Kuss, M., Lande, Joshua, Latronico, Luca, Lee, Shiu-Hang, Lemoine-Goumard, Marianne, Llena-Garde, Maja, Pepe, Monica, Longo, Francesco, Porter, Troy A., Loparco, Francesco, Lovellette, Michael N., Lubrano, Pasquale, Makeev, Andrey, Mazziotta, Mario Nicola, Michelson, Peter F., Mitthumsiri, Warit, Mizuno, Takafumi, Monte, Claudia, Pesce-Rollins, Melissa, Rainò, Silvia, Monzani, Maria Elena, Morselli, Aldo, Moskalenko, Igor V., Murgia, Simona, Naumann-Godo, Melitta, Nolan, Pat L., Norris, Jay P., Nuss, Eric, Ohsugi, Takashi, Omodei, Nicola, Rando, Riccardo, Piron, Frédéric, and Orlando, Elena

Abstract

Globular clusters with their large populations of millisecond pulsars (MSPs) are believed to be potential emitters of high-energy gamma-ray emission. Our goal is to constrain the millisecond pulsar populations in globular clusters from analysis of gamma-ray observations. We use 546 days of continuous sky-survey observations obtained with the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope to study the gamma-ray emission towards 13 globular clusters. Steady point-like high-energy gamma-ray emission has been significantly detected towards 8 globular clusters. Five of them (47 Tucanae, Omega Cen, NGC 6388, Terzan 5, and M 28) show hard spectral power indices $(0.7 < \Gamma <1.4)$ and clear evidence for an exponential cut-off in the range 1.0-2.6 GeV, which is the characteristic signature of magnetospheric emission from MSPs. Three of them (M 62, NGC 6440 and NGC 6652) also show hard spectral indices $(1.0 < \Gamma < 1.7)$, however the presence of an exponential cut-off can not be unambiguously established. Three of them (Omega Cen, NGC 6388, NGC 6652) have no known radio or X-ray MSPs yet still exhibit MSP spectral properties. From the observed gamma-ray luminosities, we estimate the total number of MSPs that is expected to be present in these globular clusters. We show that our estimates of the MSP population correlate with the stellar encounter rate and we estimate 2600-4700 MSPs in Galactic globular clusters, commensurate with previous estimates. The observation of high-energy gamma-ray emission from a globular cluster thus provides a reliable independent method to assess their millisecond pulsar populations that can be used to make constraints on the original neutron star X-ray binary population, essential for understanding the importance of binary systems in slowing the inevitable core collapse of globular clusters.

Published
2010

6. Search for gamma-ray emission from magnetars with the Fermi Large Area Telescope

Author

Abdo, Aous A., Ackermann, Markus, Ajello, Marco, Allafort, Alice, Baldini, Luca, Ballet, Jean, Barbiellini, Guido, Baring, Matthew G., Bastieri, Denis, Bellazzini, Ronaldo, Blandford, Roger D., Longo, Francesco, Loparco, Francesco, Lovellette, Michael N., Lubrano, Pasquale, Makeev, Andrey, Marelli, Martino, Mazziotta, Mario Nicola, McEnery, Julie E., Mehault, Jeremie, Michelson, Peter F., Ritz, Steven, Piron, Frédéric, Mizuno, Takafumi, Moiseev, Alex A., Monte, Claudia, Monzani, Maria Elena, Morselli, Aldo, Moskalenko, Igor V., Murgia, Simona, Naumann-Godo, Melitta, Nolan, Pat L., Sadrozinski, Hartmut F. W., Nuss, Eric, Porter, Troy A., Ohsugi, Takashi, Okumura, Akira, Omodei, Nicola, Orlando, Elena, Ormes, Jonathan F., Ozaki, Masanobu, Paneque, David, Parent, D., Saz Parkinson, Pablo M., Pepe, Monica, Rainò, Silvia, Rando, Riccardo, Razzano, Massimiliano, Rea, Nanda, Reimer, Anita, Reimer, Olaf, Reposeur, Thierry, Bloom, Elliott D., Sgrò, Carmelo, Siskind, Eric J., Smith, David A., Spandre, Gloria, Spinelli, Paolo, Strickman, Mark Samuel, Takahashi, Hiromitsu, Cecchi, Claudia, Bonamente, Emanuele, Tanaka, Takaaki, Thayer, Jana B., Thompson, David J., Tibaldo, Luigi, Torres, Diego F., Tosti, Gino, Tramacere, Andrea, Troja, Eleonora, Uchiyama, Yasunobu, Çelik, Özlem, Usher, Tracy L., Borgland, Anders W., Vandenbroucke, Justin, Vasileiou, Vlasios, Vianello, Giacomo, Vitale, Vincenzo, Waite, Anthony P., Winer, Brian L., Wood, Kent S., Yang, Zhaoyu, Chaty, Sylvain, Ziegler, Marcus, Bouvier, Aurelien, Bregeon, Jean, Brigida, Monica, Bruel, Philippe, Burnett, Thompson H., Caliandro, Giuseppe Andrea, Cameron, Robert A., Caraveo, Patrizia A., Chekhtman, Alexandre, Cheung, C. C. Teddy, Chiang, James, Ciprini, Stefano, Claus, Rachel, Conrad, Jan, Hartogh, Paul, Johannesson, Gueolaugur, Dermer, Charles Dennison, Angelis, Alessandro de, Palma, Francesco de, Dib, Rim, Dormody, Michael, Couto e Silva, Eduardo do, Drell, Persis S., Dubois, Richard, Dumora, Denis, Enoto, Teruaki, Johnson, A. S., Favuzzi, Cecilia, Frailis, Marco, Fusco, Piergiorgio, Gargano, Fabio, Gehrels, Neil, Giglietto, Nicola, Giommi, Paolo, Giordano, Francesco, Giroletti, Marcello, Glanzman, Tom, Kaspi, Victoria M., Godfrey, Gary, Grenier, Isabelle A., Grondin, Marie-Hélène, Guiriec, Sylvain, Hadasch, Daniela, Hanabata, Yoshitaka, Harding, Alice K., Hays, Elizabeth, Israel, Gian Luca, Katagiri, Hideaki, Kataoka, Jun, Knödlseder, Jürgen, Kuss, M., Lande, Joshua, Lee, Shiu-Hang, Lemoine-Goumard, Marianne, Pesce-Rollins, Melissa, Abdo, Aous A., Ackermann, Markus, Ajello, Marco, Allafort, Alice, Baldini, Luca, Ballet, Jean, Barbiellini, Guido, Baring, Matthew G., Bastieri, Denis, Bellazzini, Ronaldo, Blandford, Roger D., Longo, Francesco, Loparco, Francesco, Lovellette, Michael N., Lubrano, Pasquale, Makeev, Andrey, Marelli, Martino, Mazziotta, Mario Nicola, McEnery, Julie E., Mehault, Jeremie, Michelson, Peter F., Ritz, Steven, Piron, Frédéric, Mizuno, Takafumi, Moiseev, Alex A., Monte, Claudia, Monzani, Maria Elena, Morselli, Aldo, Moskalenko, Igor V., Murgia, Simona, Naumann-Godo, Melitta, Nolan, Pat L., Sadrozinski, Hartmut F. W., Nuss, Eric, Porter, Troy A., Ohsugi, Takashi, Okumura, Akira, Omodei, Nicola, Orlando, Elena, Ormes, Jonathan F., Ozaki, Masanobu, Paneque, David, Parent, D., Saz Parkinson, Pablo M., Pepe, Monica, Rainò, Silvia, Rando, Riccardo, Razzano, Massimiliano, Rea, Nanda, Reimer, Anita, Reimer, Olaf, Reposeur, Thierry, Bloom, Elliott D., Sgrò, Carmelo, Siskind, Eric J., Smith, David A., Spandre, Gloria, Spinelli, Paolo, Strickman, Mark Samuel, Takahashi, Hiromitsu, Cecchi, Claudia, Bonamente, Emanuele, Tanaka, Takaaki, Thayer, Jana B., Thompson, David J., Tibaldo, Luigi, Torres, Diego F., Tosti, Gino, Tramacere, Andrea, Troja, Eleonora, Uchiyama, Yasunobu, Çelik, Özlem, Usher, Tracy L., Borgland, Anders W., Vandenbroucke, Justin, Vasileiou, Vlasios, Vianello, Giacomo, Vitale, Vincenzo, Waite, Anthony P., Winer, Brian L., Wood, Kent S., Yang, Zhaoyu, Chaty, Sylvain, Ziegler, Marcus, Bouvier, Aurelien, Bregeon, Jean, Brigida, Monica, Bruel, Philippe, Burnett, Thompson H., Caliandro, Giuseppe Andrea, Cameron, Robert A., Caraveo, Patrizia A., Chekhtman, Alexandre, Cheung, C. C. Teddy, Chiang, James, Ciprini, Stefano, Claus, Rachel, Conrad, Jan, Hartogh, Paul, Johannesson, Gueolaugur, Dermer, Charles Dennison, Angelis, Alessandro de, Palma, Francesco de, Dib, Rim, Dormody, Michael, Couto e Silva, Eduardo do, Drell, Persis S., Dubois, Richard, Dumora, Denis, Enoto, Teruaki, Johnson, A. S., Favuzzi, Cecilia, Frailis, Marco, Fusco, Piergiorgio, Gargano, Fabio, Gehrels, Neil, Giglietto, Nicola, Giommi, Paolo, Giordano, Francesco, Giroletti, Marcello, Glanzman, Tom, Kaspi, Victoria M., Godfrey, Gary, Grenier, Isabelle A., Grondin, Marie-Hélène, Guiriec, Sylvain, Hadasch, Daniela, Hanabata, Yoshitaka, Harding, Alice K., Hays, Elizabeth, Israel, Gian Luca, Katagiri, Hideaki, Kataoka, Jun, Knödlseder, Jürgen, Kuss, M., Lande, Joshua, Lee, Shiu-Hang, Lemoine-Goumard, Marianne, and Pesce-Rollins, Melissa

Abstract

We report on the search for 0.1-10 GeV emission from magnetars in 17 months of Fermi Large Area Telescope (LAT) observations. No significant evidence for gamma-ray emission from any of the currently known magnetars is found. The most stringent upper limits to date on their persistent emission in the Fermi energy range are estimated between ~10–12and10–10 erg s–1 cm–2, depending on the source. We also searched for gamma-ray pulsations and possible outbursts, also with no significant detection. The upper limits derived support the presence of a cutoff at an energy below a few MeV in the persistent emission of magnetars. They also show the likely need for a revision of current models of outer-gap emission from strongly magnetized pulsars, which, in some realizations, predict detectable GeV emission from magnetars at flux levels exceeding the upper limits identified here using the Fermi-LAT observations.

Published
2010

7. Terrestrial gamma‐ray flashes in the Fermi era: Improved observations and analysis methods

Author

Briggs, Michael S., primary, Xiong, Shaolin, additional, Connaughton, Valerie, additional, Tierney, Dave, additional, Fitzpatrick, Gerard, additional, Foley, Suzanne, additional, Grove, J. Eric, additional, Chekhtman, Alexandre, additional, Gibby, Melissa, additional, Fishman, Gerald J., additional, McBreen, Shelia, additional, Chaplin, Vandiver L., additional, Guiriec, Sylvain, additional, Layden, Emily, additional, Bhat, P. N., additional, Hughes, Maximilian, additional, Greiner, Jochen, additional, von Kienlin, Andreas, additional, Kippen, R. Marc, additional, Meegan, Charles A., additional, Paciesas, William S., additional, Preece, Robert D., additional, Wilson‐Hodge, Colleen, additional, Holzworth, Robert H., additional, and Hutchins, Michael L., additional

Published
2013
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8. Radio signals from electron beams in terrestrial gamma ray flashes

Author

Connaughton, Valerie, primary, Briggs, Michael S., additional, Xiong, Shaolin, additional, Dwyer, Joseph R., additional, Hutchins, Michael L., additional, Grove, J. Eric, additional, Chekhtman, Alexandre, additional, Tierney, Dave, additional, Fitzpatrick, Gerard, additional, Foley, Suzanne, additional, McBreen, Shelia, additional, Bhat, P. N., additional, Chaplin, Vandiver L., additional, Cramer, Eric, additional, Fishman, Gerald J., additional, Holzworth, Robert H., additional, Gibby, Melissa, additional, von Kienlin, Andreas, additional, Meegan, Charles A., additional, Paciesas, William S., additional, Preece, Robert D., additional, and Wilson‐Hodge, Colleen, additional

Published
2013
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9. Einstein@Home discovers a radio-quiet gamma-ray millisecond pulsar.

Author

Clark CJ, Pletsch HJ, Wu J, Guillemot L, Kerr M, Johnson TJ, Camilo F, Salvetti D, Allen B, Anderson D, Aulbert C, Beer C, Bock O, Cuéllar A, Eggenstein HB, Fehrmann H, Kramer M, Kwang SA, Machenschalk B, Nieder L, Ackermann M, Ajello M, Baldini L, Ballet J, Barbiellini G, Bastieri D, Bellazzini R, Bissaldi E, Blandford RD, Bloom ED, Bonino R, Bottacini E, Brandt TJ, Bregeon J, Bruel P, Buehler R, Burnett TH, Buson S, Cameron RA, Caputo R, Caraveo PA, Cavazzuti E, Cecchi C, Charles E, Chekhtman A, Ciprini S, Cominsky LR, Costantin D, Cutini S, D'Ammando F, De Luca A, Desiante R, Di Venere L, Di Mauro M, Di Lalla N, Digel SW, Favuzzi C, Ferrara EC, Franckowiak A, Fukazawa Y, Funk S, Fusco P, Gargano F, Gasparrini D, Giglietto N, Giordano F, Giroletti M, Gomez-Vargas GA, Green D, Grenier IA, Guiriec S, Harding AK, Hewitt JW, Horan D, Jóhannesson G, Kensei S, Kuss M, La Mura G, Larsson S, Latronico L, Li J, Longo F, Loparco F, Lovellette MN, Lubrano P, Magill JD, Maldera S, Manfreda A, Mazziotta MN, McEnery JE, Michelson PF, Mirabal N, Mitthumsiri W, Mizuno T, Monzani ME, Morselli A, Moskalenko IV, Nuss E, Ohsugi T, Omodei N, Orienti M, Orlando E, Palatiello M, Paliya VS, de Palma F, Paneque D, Perkins JS, Persic M, Pesce-Rollins M, Porter TA, Principe G, Rainò S, Rando R, Ray PS, Razzano M, Reimer A, Reimer O, Romani RW, Saz Parkinson PM, Sgrò C, Siskind EJ, Smith DA, Spada F, Spandre G, Spinelli P, Thayer JB, Thompson DJ, Torres DF, Troja E, Vianello G, Wood K, and Wood M

Abstract

Millisecond pulsars (MSPs) are old neutron stars that spin hundreds of times per second and appear to pulsate as their emission beams cross our line of sight. To date, radio pulsations have been detected from all rotation-powered MSPs. In an attempt to discover radio-quiet gamma-ray MSPs, we used the aggregated power from the computers of tens of thousands of volunteers participating in the Einstein@Home distributed computing project to search for pulsations from unidentified gamma-ray sources in Fermi Large Area Telescope data. This survey discovered two isolated MSPs, one of which is the only known rotation-powered MSP to remain undetected in radio observations. These gamma-ray MSPs were discovered in completely blind searches without prior constraints from other observations, raising hopes for detecting MSPs from a predicted Galactic bulge population.

Published
2018
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