In twenty first century, high energy gamma-ray astronomy has become a potential branch of high energy physics to explore the extreme energetic events in the universe. Blazars are special kind of active galactic nuclei (AGN) with jet oriented at small angles to our line of sight. The relativistic motion of plasma along the jet axis increases luminosity of the jet radiation which makes blazars one of the most rapidly varying class of objects over a broad energy band (radio to-ray). PKS B1222+216 (4C +21.35; z = 0.432) is one of the brightest blazars observed in GeV energies. The multi wavelength data taken from different publicly available telescopes which includes SMARTS, SPOL-CCD of Steward observatory, Swift-XRT, Swift-UVOT and Fermi-LAT is analysed. The spectral and temporal evolution of flare states has been studied in details. This includes the study of flux-index variation, rise and decay time analysis, hardness ratio test and spectral modeling of both X-ray and GeV data. The broadband non-thermal emission from jet and thermal emission from disk produce a conventional double hump structure. The leptonic model with one emission region, moving relativistically along jet, is considered to explain the observed spectral energy distributions (SEDs). It is generally assumed that the lower energy peak comes from synchrotron and thermal emission and the high energy one is the result of inverse Compton scattering of low energy seed photons (SSC or External component). The modeling of broad band SED provides some insight about the intrinsic parameters which help us to understand the nature of different emission mechanisms inside the jet. A group of six brightest blazars (3C 273, 3C 279, 3C 454.3, CTA 102, PKS 1510-089) including PKS B1222+216 has been selected for detailed quiescent state analysis. The broadband SED modeling for all these blazars provides a comparison study of quiescent state parameters.
|
Event calendar file
