The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis
© 2017. The American Astronomical Society. All rights reserved. We present the second catalog of flaring gamma-ray sources (2FAV) detected with the Fermi All-sky Variability Analysis (FAVA), a tool that blindly searches for transients over the entire sky observed by the Large Area Telescope (LAT) on...
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Earth and Planetary Sciences S. Abdollahi M. Ackermann M. Ajello A. Albert L. Baldini J. Ballet G. Barbiellini D. Bastieri J. Becerra Gonzalez R. Bellazzini E. Bissaldi R. D. Blandford E. D. Bloom R. Bonino E. Bottacini J. Bregeon P. Bruel R. Buehler S. Buson R. A. Cameron M. Caragiulo P. A. Caraveo E. Cavazzuti C. Cecchi A. Chekhtman C. C. Cheung G. Chiaro S. Ciprini J. Conrad D. Costantin F. Costanza S. Cutini F. D'Ammando F. De Palma A. Desai R. Desiante S. W. Digel N. Di Lalla M. Di Mauro L. Di Venere B. Donaggio P. S. Drell C. Favuzzi S. J. Fegan E. C. Ferrara W. B. Focke A. Franckowiak Y. Fukazawa S. Funk P. Fusco F. Gargano D. Gasparrini N. Giglietto M. Giomi F. Giordano M. Giroletti T. Glanzman D. Green I. A. Grenier J. E. Grove L. Guillemot S. Guiriec E. Hays D. Horan T. Jogler G. Jóhannesson A. S. Johnson D. Kocevski M. Kuss G. La Mura S. Larsson L. Latronico J. Li F. Longo F. Loparco M. N. Lovellette P. Lubrano The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis |
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© 2017. The American Astronomical Society. All rights reserved. We present the second catalog of flaring gamma-ray sources (2FAV) detected with the Fermi All-sky Variability Analysis (FAVA), a tool that blindly searches for transients over the entire sky observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. With respect to the first FAVA catalog, this catalog benefits from a larger data set, the latest LAT data release (Pass 8), as well as from an improved analysis that includes likelihood techniques for a more precise localization of the transients. Applying this analysis to the first 7.4 years of Fermi observations, and in two separate energy bands 0.1-0.8 GeV and 0.8-300 GeV, a total of 4547 flares were detected with significance greater than 6σ(before trials), on the timescale of one week. Through spatial clustering of these flares, 518 variable gamma-ray sources were identified. Based on positional coincidence, likely counterparts have been found for 441 sources, mostly among the blazar class of active galactic nuclei. For 77 2FAV sources, no likely gamma-ray counterpart has been found. For each source in the catalog, we provide the time, location, and spectrum of each flaring episode. Studying the spectra of the flares, we observe a harder-when-brighter behavior for flares associated with blazars, with the exception of BL Lac flares detected in the low-energy band. The photon indexes of the flares are never significantly smaller than 1.5. For a leptonic model, and under the assumption of isotropy, this limit suggests that the spectrum of freshly accelerated electrons is never harder than P ∼ 2. |
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Hiroshima University |
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Hiroshima University S. Abdollahi M. Ackermann M. Ajello A. Albert L. Baldini J. Ballet G. Barbiellini D. Bastieri J. Becerra Gonzalez R. Bellazzini E. Bissaldi R. D. Blandford E. D. Bloom R. Bonino E. Bottacini J. Bregeon P. Bruel R. Buehler S. Buson R. A. Cameron M. Caragiulo P. A. Caraveo E. Cavazzuti C. Cecchi A. Chekhtman C. C. Cheung G. Chiaro S. Ciprini J. Conrad D. Costantin F. Costanza S. Cutini F. D'Ammando F. De Palma A. Desai R. Desiante S. W. Digel N. Di Lalla M. Di Mauro L. Di Venere B. Donaggio P. S. Drell C. Favuzzi S. J. Fegan E. C. Ferrara W. B. Focke A. Franckowiak Y. Fukazawa S. Funk P. Fusco F. Gargano D. Gasparrini N. Giglietto M. Giomi F. Giordano M. Giroletti T. Glanzman D. Green I. A. Grenier J. E. Grove L. Guillemot S. Guiriec E. Hays D. Horan T. Jogler G. Jóhannesson A. S. Johnson D. Kocevski M. Kuss G. La Mura S. Larsson L. Latronico J. Li F. Longo F. Loparco M. N. Lovellette P. Lubrano |
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S. Abdollahi M. Ackermann M. Ajello A. Albert L. Baldini J. Ballet G. Barbiellini D. Bastieri J. Becerra Gonzalez R. Bellazzini E. Bissaldi R. D. Blandford E. D. Bloom R. Bonino E. Bottacini J. Bregeon P. Bruel R. Buehler S. Buson R. A. Cameron M. Caragiulo P. A. Caraveo E. Cavazzuti C. Cecchi A. Chekhtman C. C. Cheung G. Chiaro S. Ciprini J. Conrad D. Costantin F. Costanza S. Cutini F. D'Ammando F. De Palma A. Desai R. Desiante S. W. Digel N. Di Lalla M. Di Mauro L. Di Venere B. Donaggio P. S. Drell C. Favuzzi S. J. Fegan E. C. Ferrara W. B. Focke A. Franckowiak Y. Fukazawa S. Funk P. Fusco F. Gargano D. Gasparrini N. Giglietto M. Giomi F. Giordano M. Giroletti T. Glanzman D. Green I. A. Grenier J. E. Grove L. Guillemot S. Guiriec E. Hays D. Horan T. Jogler G. Jóhannesson A. S. Johnson D. Kocevski M. Kuss G. La Mura S. Larsson L. Latronico J. Li F. Longo F. Loparco M. N. Lovellette P. Lubrano |
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S. Abdollahi |
title |
The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis |
title_short |
The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis |
title_full |
The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis |
title_fullStr |
The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis |
title_full_unstemmed |
The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis |
title_sort |
second catalog of flaring gamma-ray sources from the fermi all-sky variability analysis |
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2018 |
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https://repository.li.mahidol.ac.th/handle/123456789/42489 |
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th-mahidol.424892019-03-14T15:03:32Z The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis S. Abdollahi M. Ackermann M. Ajello A. Albert L. Baldini J. Ballet G. Barbiellini D. Bastieri J. Becerra Gonzalez R. Bellazzini E. Bissaldi R. D. Blandford E. D. Bloom R. Bonino E. Bottacini J. Bregeon P. Bruel R. Buehler S. Buson R. A. Cameron M. Caragiulo P. A. Caraveo E. Cavazzuti C. Cecchi A. Chekhtman C. C. Cheung G. Chiaro S. Ciprini J. Conrad D. Costantin F. Costanza S. Cutini F. D'Ammando F. De Palma A. Desai R. Desiante S. W. Digel N. Di Lalla M. Di Mauro L. Di Venere B. Donaggio P. S. Drell C. Favuzzi S. J. Fegan E. C. Ferrara W. B. Focke A. Franckowiak Y. Fukazawa S. Funk P. Fusco F. Gargano D. Gasparrini N. Giglietto M. Giomi F. Giordano M. Giroletti T. Glanzman D. Green I. A. Grenier J. E. Grove L. Guillemot S. Guiriec E. Hays D. Horan T. Jogler G. Jóhannesson A. S. Johnson D. Kocevski M. Kuss G. La Mura S. Larsson L. Latronico J. Li F. Longo F. Loparco M. N. Lovellette P. Lubrano Hiroshima University Deutsche Elektronen-Synchrotron Clemson University Los Alamos National Laboratory Università di Pisa Universite Paris 7- Denis Diderot Istituto Nazionale di Fisica Nucleare, Roma Università degli Studi di Trieste Istituto Nazionale Di Fisica Nucleare, Sezione di Padova Università degli Studi di Padova NASA Goddard Space Flight Center University of Maryland Istituto Nazionale Di Fisica Nucleare, Sezione di Pisa Kavli Institute for Particle Astrophysics and Cosmology Università degli Studi di Torino Laboratoire Univers et Particules de Montpellier Laboratoire Leprince-Ringuet Università degli Studi di Bari INAF Istituto di Astrofisica Spaziale e Fisica Cosmica, Milan Agenzia Spaziale Italiana Università degli Studi di Perugia George Mason University, Fairfax Campus Naval Research Laboratory Stockholms universitet Oskar Klein Centre for Cosmoparticle Physics INAF Istituto di Astrofisica Spaziale e Fisica Cosmica, Bologna Alma Mater Studiorum Università di Bologna Università degli Studi di Napoli Federico II Università degli Studi di Udine Erlangen Centre for Astroparticle Physics Universite d'Orleans Institut National des Sciences de l'Univers Friedrich-Alexander-Universität Erlangen-Nürnberg University Science Institute Reykjavik The Royal Institute of Technology (KTH) Universitat Autònoma de Barcelona Mahidol University Max Planck Institut für Physik (Werner-Heisenberg-Institut) Osservatorio Astronomico di Trieste Earth and Planetary Sciences © 2017. The American Astronomical Society. All rights reserved. We present the second catalog of flaring gamma-ray sources (2FAV) detected with the Fermi All-sky Variability Analysis (FAVA), a tool that blindly searches for transients over the entire sky observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. With respect to the first FAVA catalog, this catalog benefits from a larger data set, the latest LAT data release (Pass 8), as well as from an improved analysis that includes likelihood techniques for a more precise localization of the transients. Applying this analysis to the first 7.4 years of Fermi observations, and in two separate energy bands 0.1-0.8 GeV and 0.8-300 GeV, a total of 4547 flares were detected with significance greater than 6σ(before trials), on the timescale of one week. Through spatial clustering of these flares, 518 variable gamma-ray sources were identified. Based on positional coincidence, likely counterparts have been found for 441 sources, mostly among the blazar class of active galactic nuclei. For 77 2FAV sources, no likely gamma-ray counterpart has been found. For each source in the catalog, we provide the time, location, and spectrum of each flaring episode. Studying the spectra of the flares, we observe a harder-when-brighter behavior for flares associated with blazars, with the exception of BL Lac flares detected in the low-energy band. The photon indexes of the flares are never significantly smaller than 1.5. For a leptonic model, and under the assumption of isotropy, this limit suggests that the spectrum of freshly accelerated electrons is never harder than P ∼ 2. 2018-12-21T07:26:58Z 2019-03-14T08:03:32Z 2018-12-21T07:26:58Z 2019-03-14T08:03:32Z 2017-09-01 Article Astrophysical Journal. Vol.846, No.1 (2017) 10.3847/1538-4357/aa8092 15384357 0004637X 2-s2.0-85029106472 https://repository.li.mahidol.ac.th/handle/123456789/42489 Mahidol University SCOPUS https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85029106472&origin=inward |