A structured leptonic jet model of the orphan TeV gamma-ray flares in TeV blazars

• Published in: The Astrophysical journal 2006-11, Vol.651 (1), p.113-119
• Main Authors: KUSUNOSE, Masaaki, TAKAHARA, Fumio
• Format: Article
• Language: English
• Subjects: Astronomy; Earth, ocean, space; Exact sciences and technology
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/507403

The emission spectra of TeV blazars extend up to tens of TeV, and the emission mechanism of the TeV g-rays is explained by synchrotron self-Compton scattering in leptonic models. In these models the time variabilities of X-rays and TeV g-rays are correlated. However, recent observations of 1ES 1959+65.0 and Mrk421 have found the "orphan" TeV g-ray flares, i.e., TeV g-ray flares without simultaneous X-ray flares. In this paper we propose a model for the orphan TeV g-ray flares, employing an inhomogeneous leptonic jet model. After a primary flare that accompanies flare-up both in X-rays and TeV g-rays, radiation propagates in various directions in the comoving frame of the jet. When a dense region in the jet receives the radiation, X-rays are scattered by relativistic electrons/positrons to become TeV g-rays. These g-ray photons are observed as an orphan TeV g-ray flare. The observed delay time between the primary and orphan flares is about 2 weeks, and this is accounted for in our model for parameters such as = 20, d = 4 x 10 super(17) cm, a=3, and = 1, where is the bulk Lorentz factor of the jet, d is the distance between the central black hole and the primary flare site, a/ is the angle between the jet axis and the direction of the motion of the dense region that scatters incoming X-rays produced by the primary flare, and / is the angle between the jet axis and the line of sight.