S. Archambault, T. Aune, B. Behera, M. Beilicke, W. Benbow, K. Berger, R. Bird, Jonathan Biteau, V. Bugaev, K. Byrum, J. V. Cardenzana, M. Cerruti, Xuhui Chen, L. Ciupik, M. P. Connolly, Wei Cui, J. Dumm, M. Errando, A. Falcone, Simone Federici, Q. Feng, J. P. Finley, H. Fleischhack, L. Fortson, A. Furniss, N. Galante, G. H. Gillanders, S. Griffin, S. T. Griffiths, J. Grube, G. Gyuk, D. Hanna, J. Holder, G. Hughes, T. B. Humensky, C. A. Johnson, P. Kaaret, M. Kertzman, Y. Khassen, D. Kieda, H. Krawczynski, F. Krennrich, S. Kumar, M. J. Lang, A. S. Madhavan, G. Maier, A. McCann, K. Meagher, P. Moriarty, R. Mukherjee, Daniel Nieto, R. A. Ong, A. N. Otte, N. Park, Martin Pohl, A. Popkow, H. Prokoph, J. Quinn, K. Ragan, J. Rajotte, L. C. Reyes, P. T. Reynolds, G. T. Richards, E. Roache, G. H. Sembroski, K. Shahinyan, D. Staszak, Igor O. Telezhinsky, J. V. Tucci, J. Tyler, A. Varlotta, V. V. Vassiliev, S. Vincent, S. P. Wakely, A. Weinstein, R. Welsing, Alina Wilhelm, D. A. Williams, Margit Ackermann, M. Ajello, A. Albert, L. Baldini, D. Bastieri, R. Bellazzini, E. Bissaldi, Johan Bregeon, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, E. Cavazzuti, E. Charles, J. Chiang, S. Ciprini, R. Claus, S. Cutini, A. de Angelis, F. de Palma, C. D. Dermer, S. W. Digel, L. Di Venere, P. S. Drell, C. Favuzzi, A. Franckowiak, P. Fusco, F. Gargano, D. Gasparrini, N. Giglietto, F. Giordano, M. Giroletti, I. A. Grenier, S. Guiriec, T. Jogler, M. Kuss, S. Larsson, L. Latronico, F. Longo, F. Loparco, P. Lubrano, G. M. Madejski, M. Mayer, Mario Nicola Mazziotta, P. F. Michelson, T. Mizuno, M. E. Monzani, Aldo Morselli, S. Murgia, E. Nuss, T. Ohsugi, J. F. Ormes, D. Paneque, J. S. Perkins, F. Piron, G. Pivato, S. Raino, M. Razzano, A. Reimer, Olaf Reimer, S. Ritz, M. Schaal, C. Sgro, E. J. Siskind, P. Spinelli, H. Takahashi, L. Tibaldo, M. Tinivella, E. Troja, G. Vianello, M. Werner, M. Wood
- We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z >= 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 +/- 0.3) x 10(-7) photons m(-2) s(-1) above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02 +/- 0.08) x 10-7 photons m(-2) s(-1) above 120 GeV. The measured differential very high energy (VHE; E >= 100 GeV) spectral indices are Gamma = 3.8 +/- 0.3, 4.3 +/- 0.6 and 4.5 +/- 0.2 in 2009, 2011, and 2013, respectively. No significant spectral change across the observation epochs is detected.We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z >= 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 +/- 0.3) x 10(-7) photons m(-2) s(-1) above 120 GeV in 2009 and 2011 as compared to the flux measured in 2013, corresponding to (1.02 +/- 0.08) x 10-7 photons m(-2) s(-1) above 120 GeV. The measured differential very high energy (VHE; E >= 100 GeV) spectral indices are Gamma = 3.8 +/- 0.3, 4.3 +/- 0.6 and 4.5 +/- 0.2 in 2009, 2011, and 2013, respectively. No significant spectral change across the observation epochs is detected. We find no evidence for variability at gamma-ray opacities of greater than tau = 2, where it is postulated that any variability would be small and occur on timescales longer than a year if hadronic cosmic-ray interactions with extragalactic photon fields provide a secondary VHE photon flux. The data cannot rule out such variability due to low statistics.…
MetadatenAuthor details: | S. Archambault, T. Aune, B. Behera, M. Beilicke, W. Benbow, K. Berger, R. Bird, Jonathan Biteau, V. Bugaev, K. Byrum, J. V. Cardenzana, M. Cerruti, Xuhui Chen, L. Ciupik, M. P. Connolly, Wei Cui, J. Dumm, M. Errando, A. Falcone, Simone FedericiGND, Q. Feng, J. P. Finley, H. Fleischhack, L. Fortson, A. Furniss, N. Galante, G. H. Gillanders, S. Griffin, S. T. Griffiths, J. Grube, G. Gyuk, D. Hanna, J. Holder, G. Hughes, T. B. Humensky, C. A. Johnson, P. Kaaret, M. Kertzman, Y. Khassen, D. Kieda, H. Krawczynski, F. Krennrich, S. Kumar, M. J. Lang, A. S. Madhavan, G. Maier, A. McCann, K. Meagher, P. Moriarty, R. Mukherjee, Daniel Nieto, R. A. Ong, A. N. Otte, N. Park, Martin PohlORCiDGND, A. Popkow, H. Prokoph, J. Quinn, K. Ragan, J. Rajotte, L. C. Reyes, P. T. Reynolds, G. T. Richards, E. Roache, G. H. Sembroski, K. Shahinyan, D. Staszak, Igor O. TelezhinskyORCiD, J. V. Tucci, J. Tyler, A. Varlotta, V. V. Vassiliev, S. Vincent, S. P. Wakely, A. Weinstein, R. Welsing, Alina WilhelmORCiDGND, D. A. Williams, Margit Ackermann, M. Ajello, A. Albert, L. Baldini, D. Bastieri, R. Bellazzini, E. Bissaldi, Johan Bregeon, R. Buehler, S. Buson, G. A. Caliandro, R. A. Cameron, P. A. Caraveo, E. Cavazzuti, E. Charles, J. Chiang, S. Ciprini, R. Claus, S. Cutini, A. de Angelis, F. de Palma, C. D. Dermer, S. W. Digel, L. Di Venere, P. S. Drell, C. Favuzzi, A. Franckowiak, P. Fusco, F. Gargano, D. Gasparrini, N. Giglietto, F. Giordano, M. Giroletti, I. A. Grenier, S. Guiriec, T. Jogler, M. Kuss, S. Larsson, L. Latronico, F. Longo, F. Loparco, P. Lubrano, G. M. Madejski, M. Mayer, Mario Nicola MazziottaORCiD, P. F. Michelson, T. Mizuno, M. E. Monzani, Aldo Morselli, S. Murgia, E. Nuss, T. Ohsugi, J. F. Ormes, D. Paneque, J. S. Perkins, F. Piron, G. Pivato, S. Raino, M. Razzano, A. Reimer, Olaf Reimer, S. Ritz, M. Schaal, C. Sgro, E. J. Siskind, P. Spinelli, H. Takahashi, L. Tibaldo, M. Tinivella, E. Troja, G. Vianello, M. Werner, M. Wood |
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DOI: | https://doi.org/10.1088/2041-8205/785/1/L16 |
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ISSN: | 2041-8205 |
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ISSN: | 2041-8213 |
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Title of parent work (English): | The astrophysical journal : an international review of spectroscopy and astronomical physics ; Part 2, Letters |
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Publisher: | IOP Publ. Ltd. |
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Place of publishing: | Bristol |
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Publication type: | Article |
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Language: | English |
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Year of first publication: | 2014 |
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Publication year: | 2014 |
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Creating corporation: | VERITAS Collaboration, Fermi LAT Collaboration |
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Release date: | 2017/03/27 |
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Tag: | BL Lacertae objects: individual (PKS 1424+240)-cosmic background radiation; gamma rays: galaxies |
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Volume: | 785 |
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Issue: | 1 |
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Number of pages: | 8 |
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Funding institution: | U.S. Department of Energy Office of Science; U.S. National Science
Foundation; Smithsonian Institution; NSERC in Canada; Science Foundation
Ireland [SFI 10/RFP/AST2748]; STFC in the UK; NASA through the Space
Telescope Science Institute [HST-GO-12863]; NASA [NAS 5-26555]; INAF in
Italy; CNES in France |
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Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Physik und Astronomie |
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Peer review: | Referiert |
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