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A hard gamma-ray flare from 3C 279 in 2013 December

Paliya, Vaidehi S. and Diltz, Chris and Böttcher, Markus and Stalin, C. S. and Buckley, David (2016) A hard gamma-ray flare from 3C 279 in 2013 December. Astrophysical Journal, 817 (1). Art. No. 61. ISSN 0004-637X. doi:10.3847/0004-637X/817/1/61.

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The blazar 3C 279 exhibited twin γ-ray flares of similar intensity in 2013 December and 2014 April. In this work, we present a detailed multi-wavelength analysis of the 2013 December flaring event. Multi-frequency observations reveal the uncorrelated variability patterns with X-ray and optical–UV fluxes peaking after the γ-ray maximum. The broadband spectral energy distribution (SED) at the peak of the γ-ray activity shows a rising γ-ray spectrum but a declining optical–UV flux. This observation along with the detection of uncorrelated variability behavior rules out the one-zone leptonic emission scenario. We, therefore, adopt two independent methodologies to explain the SED: a time-dependent lepto-hadronic modeling and a two-zone leptonic radiative modeling approach. In the lepto-hadronic modeling, a distribution of electrons and protons subjected to a randomly orientated magnetic field produces synchrotron radiation. Electron synchrotron is used to explain the IR to UV emission while proton synchrotron emission is used to explain the high-energy γ-ray emission. A combination of both electron synchrotron self-Compton emission and proton synchrotron emission is used to explain the X-ray spectral break seen during the later stage of the flare. In the two-zone modeling, we assume a large emission region emitting primarily in IR to X-rays and γ-rays to come primarily from a fast-moving compact emission region. We conclude by noting that within a span of four months, 3C 279 has shown the dominance of a variety of radiative processes over each other and this reflects the complexity involved in understanding the physical properties of blazar jets in general.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Paliya, Vaidehi S.0000-0001-7774-5308
Stalin, C. S.0000-0002-4998-1861
Buckley, David0000-0002-7004-9956
Additional Information:© 2016 The American Astronomical Society. Received 2015 August 4; accepted 2015 November 30; published 2016 January 20. We are thankful to the referee for providing a constructive report. This research has made use of data, software, and/or web tools obtained from NASAs High Energy Astrophysics Science Archive Research Center (HEASARC), a service of Goddard Space Flight Center and the Smithsonian Astrophysical Observatory. Part of this work is based on archival data, software, or online services provided by the ASI Science Data Center (ASDC). This research has made use of the XRT Data Analysis Software (XRTDAS) developed under the responsibility of the ASDC, Italy. This research has also made use of the NuSTAR Data Analysis Software (NuSTARDAS) jointly developed by the ASI Science Data Center (ASDC, Italy) and the California Institute of Technology (Caltech, USA). Data from the Steward Observatory spectropolarimetric monitoring project were used. This program is supported by Fermi Guest Investigator grants NNX08AW56G, NNX09AU10G, and NNX12AO93G. This paper has made use of up-to-date SMARTS optical/near-infrared light curves that are available at Use of the Hydra cluster at the Indian Institute of Astrophysics is acknowledged. The work of M.B. is supported by the South African Research Chair Initiative (SARChI) of the Department of Science and Technology and the National Research Foundation of South Africa.
Funding AgencyGrant Number
Department of Science and Technology (South Africa)UNSPECIFIED
National Research Foundation (South Africa)UNSPECIFIED
Subject Keywords:galaxies: active – galaxies: jets – gamma rays: galaxies – quasars: individual (3C 279)
Issue or Number:1
Record Number:CaltechAUTHORS:20160131-143450702
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Official Citation:Vaidehi S. Paliya et al 2016 ApJ 817 61
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:64109
Deposited By: Joy Painter
Deposited On:03 Feb 2016 20:39
Last Modified:10 Nov 2021 23:26

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