Relativistic jets as X-ray and gamma-ray sources

Abstract

The radiation from beamed relativistic jets associated with bright compact extragalactic radio sources is considered and used in the interpretation of extragalactic X-ray and gamma-ray sources. Synchrotron and inverse-Compton spectra of an inhomogeneous relativistic jet are calculated on the basis of a power-law relativistic electron distribution emission model for the cases of a resolved jet and an unresolved inhomogeneous jet. It is shown that the source nonuniformity in an unresolved jet may give rise to a spectrum quite different from the local emission spectrum. The model is then applied to the spectra of BL Lac objects and the quasar 3C 273, and it is pointed out that various observed features in BL Lac object spectra and the radio and gamma-ray emission from 3C 273 may be attributed to relativistic jets. In addition, the postulated local synchrotron spectrum is applied to the resolved X-ray jet in Cen A.