Gamma-Ray Flaring Activity from the Gravitationally Lensed Blazar PKS 1830-211 Observed by Fermi LAT
Journal
Date Issued
2015
Author(s)
Abdo, A. A.
•
Ackermann, M.
•
Ajello, M.
•
Allafort, A.
•
Amin, M. A.
•
Baldini, L.
•
Barbiellini, G.
•
Bastieri, D.
•
Bechtol, K.
•
Bellazzini, R.
•
Blandford, R. D.
•
Bonamente, E.
•
Borgland, A. W.
•
Bregeon, J.
•
Brigida, M.
•
Buehler, R.
•
Bulmash, D.
•
Buson, S.
•
Caliandro, G. A.
•
Cameron, R. A.
•
•
Cavazzuti, E.
•
Cecchi, C.
•
Charles, E.
•
Cheung, C. C.
•
Chiang, J.
•
Chiaro, G.
•
Ciprini, S.
•
Claus, R.
•
Cohen-Tanugi, J.
•
Conrad, J.
•
Corbet, R. H. D.
•
Cutini, S.
•
•
de Angelis, A.
•
de Palma, F.
•
Dermer, C. D.
•
Drell, P. S.
•
Drlica-Wagner, A.
•
Favuzzi, C.
•
Finke, J.
•
Focke, W. B.
•
Fukazawa, Y.
•
Fusco, P.
•
Gargano, F.
•
Gasparrini, D.
•
Gehrels, N.
•
Giglietto, N.
•
Giordano, F.
•
•
Glanzman, T.
•
Grenier, I. A.
•
Grove, J. E.
•
Guiriec, S.
•
Hadasch, D.
•
Hayashida, M.
•
Hays, E.
•
Hughes, R. E.
•
Inoue, Y.
•
Jackson, M. S.
•
Jogler, T.
•
Jóhannesson, G.
•
Johnson, A. S.
•
Kamae, T.
•
Knödlseder, J.
•
Kuss, M.
•
Lande, J.
•
Larsson, S.
•
Latronico, L.
•
Longo, F.
•
Loparco, F.
•
Lott, B.
•
Lovellette, M. N.
•
Lubrano, P.
•
Madejski, G. M.
•
Mazziotta, M. N.
•
Mehault, J.
•
Michelson, P. F.
•
Mizuno, T.
•
Monzani, M. E.
•
Morselli, A.
•
Moskalenko, I. V.
•
Murgia, S.
•
Nemmen, R.
•
Nuss, E.
•
Ohno, M.
•
Ohsugi, T.
•
Paneque, D.
•
Perkins, J. S.
•
Pesce-Rollins, M.
•
Piron, F.
•
Pivato, G.
•
Porter, T. A.
•
Rainò, S.
•
Rando, R.
•
Razzano, M.
•
Reimer, A.
•
Reimer, O.
•
Reyes, L. C.
•
Ritz, S.
•
Romoli, C.
•
Roth, M.
•
Saz Parkinson, P. M.
•
Sgrò, C.
•
Siskind, E. J.
•
Spandre, G.
•
Spinelli, P.
•
Takahashi, H.
•
Takeuchi, Y.
•
Tanaka, T.
•
Thayer, J. G.
•
Thayer, J. B.
•
Thompson, D. J.
•
Tibaldo, L.
•
Tinivella, M.
•
Torres, D. F.
•
Tosti, G.
•
Troja, E.
•
Tronconi, V.
•
Usher, T. L.
•
Vandenbroucke, J.
•
Vasileiou, V.
•
Vianello, G.
•
Vitale, V.
•
Waite, A. P.
•
Werner, M.
•
Winer, B. L.
•
Wood, K. S.
Description
We thank the anonymous referees for useful comments that improved the paper. S.C. thanks Dr. R. Porcas of MPIfR, Bonn, Germany, for a useful discussion during the course of this work. 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 includes observations obtained with the NASA Swift Gamma-Ray Burst Explorer. Swift is a MIDEX Gamma Ray Burst mission led by NASA with participation of Italy and the UK. This research has made use of the Smithsonian/NASA's ADS bibliographic database. This research has made use of the archives and services of the ASI Science Data Center (ASDC), a facility of the Italian Space Agency (ASI Headquarters, Rome, Italy). This research has made use of the NASA/IPAC NED database (JPL CalTech and NASA, USA). Facilities: Fermi LAT , Swift
Abstract
The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope routinely detects the MeV-peaked flat-spectrum radio quasar PKS 1830-211 (z = 2.507). Its apparent isotropic γ-ray luminosity (E > 100 MeV), averaged over ~3 years of observations and peaking on 2010 October 14/15 at 2.9 × 1050 erg s-1, makes it among the brightest high-redshift Fermi blazars. No published model with a single lens can account for all of the observed characteristics of this complex system. Based on radio observations, one expects time-delayed variability to follow about 25 days after a primary flare, with flux about a factor of 1.5 less. Two large γ-ray flares of PKS 1830-211 have been detected by the LAT in the considered period, and no substantial evidence for such a delayed activity was found. This allows us to place a lower limit of about 6 on the γ-ray flux ratio between the two lensed images. Swift XRT observations from a dedicated Target of Opportunity program indicate a hard spectrum with no significant correlation of X-ray flux with the γ-ray variability. The spectral energy distribution can be modeled with inverse Compton scattering of thermal photons from the dusty torus. The implications of the LAT data in terms of variability, the lack of evident delayed flare events, and different radio and γ-ray flux ratios are discussed. Microlensing effects, absorption, size and location of the emitting regions, the complex mass distribution of the system, an energy-dependent inner structure of the source, and flux suppression by the lens galaxy for one image path may be considered as hypotheses for understanding our results.
Volume
799
Issue
2
Start page
143
Issn Identifier
0004-637X
Ads BibCode
2015ApJ...799..143A
Rights
open.access
File(s)![Thumbnail Image]()
Loading...
Name
Abdo_2015_ApJ_799_143.pdf
Description
PDF editoriale
Size
1015.57 KB
Format
Adobe PDF
Checksum (MD5)
a4469100f0e259d84274f408ec10cc05