2008/07/24 by M. Kusunose, Masaaki Kusunose, Fumio Takahara +1 · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Blazar #Compton scattering #Dark Matter and Cosmic Phenomena #Flare #Flux (metallurgy) #Jet (fluid) #Lorentz factor #Particle acceleration #Relativity and Gravitational Theory #Synchrotron #Synchrotron radiation #astro-ph
paper · pdf · doi:10.1086/589233
9 pages, 5 figures, 2 tables, to appear in the Astrophysical Journal, Vol. 682
arxiv created 2008/07/24 · openalex publication_date 2008/07/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
H.E.S.S. observed TeV blazar PKS 2155–304 in a strong flare state in 2006 July. The TeV flux varied on timescale as short as a few minutes, which sets strong constraints on the properties of the emission region. By use of the synchrotron self-Compton model, we found that models with the bulk Lorentz factor ~100, the size of the emission region ~10 15 cm, and magnetic field ~0.1 G explain the observed spectral energy distribution and the flare timescale of ~a few minutes. This model with a large value of Γ accounts for the emission spectrum not only in the TeV band but also in the X-ray band. The major cooling process of electrons/positrons in the jet is inverse Compton scattering off synchrotron photons. The energy content of the jet is highly dominated by particle kinetic energy over magnetic energy.