Probing IC/CMB Interpretation for the X-ray knots of AGN through VHE observations

Abstract

Detection of hard X-ray spectrum from the kilo-parsec scale jet of active galactic nuclei cannot be accounted to the synchrotron emission mechanism from the electron distribution responsible for the radio/optical emission. Alternate explanations are the inverse Compton scattering of cosmic microwave background photons (IC/CMB) or synchrotron emission from a second electron population. When the X-ray emission is interpreted as IC/CMB process, the Compton spectrum peak at GeV energy and were predicted to be the Fermi candidate sources. The non-detection of significant gamma ray flux from these galaxies by Fermi disfavoured the IC/CMB interpretation of the high energy emission. We extend this study to predict the very high energy (VHE) gamma ray emission due to IC/CMB model which can be investigated by Cherenkov Telescope Array(CTA). The model parameters deciding the broadband spectral energy distribution are estimated using analytical approximation of the emissivity functions. The emission model is extrapolated to VHE energy and then compared with the CTAO sensitivity. Particularly, we selected the sources for which the IC/CMB model is not ruled out by initial Fermi observations.Comment: Submitted to MNRAS Main Joura