Abstract Details
| Name: PRANJUPRIYA GOSWAMI Affiliation: TEZPUR UNIVERSITY Conference ID: ASI2018_1188 Title : X-ray spectral curvature of high energy blazars with NuSTAR observations Authors and Co-Authors : Atreyee Sinha (AstroParticule et Cosmologie, Universite Paris Diderot, Paris), Ranjeev Misra (IUCAA, Pune), Sunder Sahayanathan(BARC, Mumbai), Rupjyoti Gogoi (Tezpur University) Abstract Type : Contributed Talk Abstract Category : Extragalactic astronomy Abstract : The synchrotron emission from the accelerating electrons in the magnetic field of a jet is responsible for the X-ray emission in high energy peaked blazars. The X-ray spectrum shows a clear curvature, being well modelled by a log parabola model. Empirically fitting the spectra with a log parabola model have shown that the curvature parameter($\beta$) varies from source to source and for different observations of the same source. It has been reported that curvature is correlated with the flux and the local photon index at a fixed energy. In order to find the origin of the X-ray spectral curvature we assumed that in the acceleration region producing the non-thermal electrons, the escape time scale of the electron is energy dependent. We fit the NuSTAR spectra for Mkn 421 and 4 more HBLs along with 2 FSRQs with the prediction that synchrotron spectrum is arising from such a system. Such a synchrotron spectrum can be approximated to be a log parabola over a small range of energy and we naturally find that both models fit the observations equally well. This can have interesting implications regarding the origin of the observed spectral curvatures. |