Exploring High-energy Emission from the BL Lacertae Object S5 0716+714 with the Fermi Large Area Telescope

• We present the results of an extensive gamma-ray data analysis of the emission from the blazar S5 0716+714 with the primary motivation to study its temporal and spectral variability behavior. In this work, we extract a 10 days binned gamma-ray light curve from 2008 August 4 to 2016 April 27 in the energy range of 0.1-300 GeV and identify six outburst periods with peak flux of >4 x 10(-7) ph cm(-2) s(-1) from this highly variable source. The brightest flares are identified by zooming in these outburst periods to 1 day binning and using the Bayesian Blocks algorithm. The fastest variability timescale is found to be 1.5 0.3 hr at MJD 57128.01 0.01 with a peak flux above 100 MeV of (26.8 6.9) x 10(-7) ph cm(-2) s(-1). No hint of periodic modulations has been detected for the light curve of S5 0716+714. During the outburst phases, the gamma-ray spectrum shows an obvious spectral break with a break energy between 0.93 and 6.90 GeV energies, which may be caused by an intrinsic break in the energy distribution of radiating particles. The five highest-energy photons, with E > 100 GeV, imply that the high-energy emission from this source may originate from a moving emission region in a helical path upstream in the jet. The spectral behavior and temporal characteristics of the individual flares indicate that the location of the emission region lies in the sub-parsec scale (r(gamma) < 0.85 pc).

Ämnesord

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

NATURVETENSKAP  -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Astronomy, Astrophysics and Cosmology (hsv//eng)

Nyckelord

Blazars

BL Lacertae objects

Relativistic jets

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