MINUTE-TIMESCALE > 100 MeV gamma-RAY VARIABILITY DURING THE GIANT OUTBURST OF QUASAR 3C 279 OBSERVED BY FERMI-LAT IN 2015 JUNE

Uchiyama Y, Sikora M, Nalewajko K, Ohsugi T, Maldera S, Negro M, La Mura G, Mirabal N, Anantua R, Yuan Y, Cavazzuti E, Bonino R, Moskalenko IV, Stawarz L, Orlando E, Porter TA, Reimer A, Lott B, Simone D, Buehler R, Caragiulo M, Caraveo PA, Spada F, Cecchi C, Cheung CC, Costanza F, Drell PS, Di Venere L, Monzani ME, D'Ammando F, Michelson PF, Spinelli P, Gonzalez JB, Bissaldi E, Fusco P, Funk S, Ferrara EC, Chiaro G, Fukazawa Y, Asano K, Johannesson G, Ackermann M, Guillemot L, Caliandro GA, Cameron RA, Chiang J, Principe G, Grenier IA, Bruel P, Larsson S, Bloom ED, Pesce-Rollins M, Gargano F, Madejski GM, Di Mauro M, Digel SW, Di Lalla N, Hayashida M, Hays E, Pivato G, Zimmer S, Giroletti M, Magill JD, Desiante R, De Palma F, Favuzzi C, Troja E, Torres DF, Kensei S, Scargle JD, Thompson DJ, Li J, Morselli A, Paneque D, Guiriec S, Cutini S, Perkins JS, Nuss E, Razzano M, Razzaque S, Siskind EJ, Sgro C, Fegan SJ, Cohen-Tanugi J, Horan D, Thayer JB, Bellazzini R, Bastieri D, Barbiellini G, Mizuno T, Mazziotta MN, Mayer M, Gasparrini D, Kocevski D, Kuss M, Ciprini S, Blandford RD, Rando R, Piron F, Lubrano P, Baldini L, Longo F, Latronico L, Lovellette MN, Manfreda A, Bottacini E, Giglietto N, Loparco F, Giordano F (2016)

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2016

Journal

Publisher: American Astronomical Society

Book Volume: 824

Article Number: L20

Journal Issue: 2

DOI: 10.3847/2041-8205/824/2/L20

Abstract

On 2015 June 16, Fermi- LAT observed a giant outburst from the flat spectrum radio quasar 3C 279 with a peak >100 MeV flux of similar to 3.6 x 10(-5) photons cm(-2) s(-1), averaged over orbital period intervals. It is historically the highest gamma-ray flux observed from the source, including past EGRET observations, with the gamma-ray isotropic luminosity reaching similar to 10(49) erg s(-1). During the outburst, the Fermi spacecraft, which has an orbital period of 95.4 minutes, was operated in a special pointing mode to optimize the exposure for 3C 279. For the first time, significant flux variability at sub-orbital timescales was found in blazar observations by Fermi- LAT. The source flux variability was resolved down to 2-minute binned timescales, with flux doubling times of less than 5 minutes. The observed minute-scale variability suggests a very compact emission region at hundreds of Schwarzschild radii from the central engine in conical jet models. A minimum bulk jet Lorentz factor (Gamma) of 35 is necessary to avoid both internal gamma-ray absorption and super-Eddington jet power. In the standard external radiation Comptonization scenario, G should be at least 50 to avoid overproducing the synchrotron self-Compton component. However, this predicts extremely low magnetization (similar to 5 x 10(-4)). Equipartition requires Gamma as high as 120, unless the emitting region is a small fraction of the dissipation region. Alternatively, we consider. rays originating as synchrotron radiation of gamma e similar to 1.6 x 10(6) electrons, in a magnetic field B similar to 1.3 kG, accelerated by strong electric fields E similar to B in the process of magnetoluminescence. At such short distance scales, one cannot immediately exclude the production of gamma-rays in hadronic processes.

Authors with CRIS profile

Involved external institutions

Nicolaus Copernicus Astronomical Centre of the Polish Academy of Sciences Poland (PL) National Institute for Nuclear Physics / Istituto Nazionale di Fisica Nucleare (INFN) Italy (IT) National Aeronautics and Space Administration (NASA) United States (USA) (US) Stanford University United States (USA) (US) Italian Space Agency / Agenzia Spaziale Italiana (ASI) Italy (IT) Jagiellonian University / Uniwersytet Jagielloński (UJ) Poland (PL) Université Bordeaux 1, Sciences et Technologies France (FR) Deutsches Elektronen-Synchrotron DESY Germany (DE) U.S. Naval Research Laboratory United States (USA) (US) University of Bari Aldo Moro / Università degli Studi di Bari Aldo Moro Italy (IT) University of Padua / Universita degli Studi di Padova Italy (IT) Hiroshima University Japan (JP) University of Tokyo Japan (JP) University of Iceland (UI) / Háskóli Íslands Iceland (IS) University of Orléans / Université d'Orléans France (FR) École Polytechnique - Université Paris-Saclay France (FR) University of Paris 7 - Denis Diderot / Université Paris VII Denis Diderot France (FR) AlbaNova University Centre / Kungliga Tekniska Högskolan AlbaNova Universitetscentrum Sweden (SE) University of Geneva / Université de Genève (UNIGE) Switzerland (CH) University of Maryland United States (USA) (US) National Institute for Astrophysics / Istituto Nazionale Astrofisica (INAF) Italy (IT) Spanish National Research Council / Consejo Superior de Investigaciones Científicas (CSIC) Spain (ES) University of Montpellier / Université Montpellier France (FR) University of Johannesburg South Africa (ZA) NYCB Real-Time Computing, Inc. United States (USA) (US)

How to cite

APA:

Uchiyama, Y., Sikora, M., Nalewajko, K., Ohsugi, T., Maldera, S., Negro, M.,... Giordano, F. (2016). MINUTE-TIMESCALE > 100 MeV gamma-RAY VARIABILITY DURING THE GIANT OUTBURST OF QUASAR 3C 279 OBSERVED BY FERMI-LAT IN 2015 JUNE. Astrophysical Journal Letters, 824(2). https://dx.doi.org/10.3847/2041-8205/824/2/L20

MLA:

Uchiyama, Y., et al. "MINUTE-TIMESCALE > 100 MeV gamma-RAY VARIABILITY DURING THE GIANT OUTBURST OF QUASAR 3C 279 OBSERVED BY FERMI-LAT IN 2015 JUNE." Astrophysical Journal Letters 824.2 (2016).

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