Name: Abhijit Kayal
Affiliation: Physical Research Laboratory
Conference ID : ASI2022_413
Title : Hard X-ray view of the associated HI 21 cm absorption detected radio AGN
Authors : Abhijit Kayal (PRL, Ahmedabad), Veeresh Singh (PRL, Ahmedabad)
Abstract Type: Poster
Abstract Category : Extragalactic Astronomy
Abstract : The dusty and gaseous circumnuclear environment in active galactic nuclei (AGN) can be traced via X-ray spectral modeling. The cold neutral medium can also be inferred via the detection of the HI 21 cm absorption line. The higher detection rate of HI absorption in compact radio galaxies infer the location of absorbing gas closer to the AGN, however, the exact location of HI absorbing gas is a subject of investigation. Using XMM-N and NuSTAR observations, we model the broad-band X-ray spectra of a sample AGN with associated HI 21 cm absorption. Our results suggest that the associated HI absorbed radio sources are likely to constitute a substantial fraction of Compton-thick AGN (X-ray column density N_H > 10^24 cm^-2) that can be characterized with a heavily absorbed direct power law component and a reflection component arising from the toroidal-shaped obscuring material around AGN. In this presentation, we aim to demonstrate the importance of hard X-ray observations of a statistically large sample of HI absorbed AGN to infer the connection between X-ray and radio absorbing components. Our study also examines the possibility of whether X-ray absorption can be used as an indicator for the detection of associated HI absorption in radio AGN.