Kavli Affiliate: Claudio Ricci
| First 5 Authors: Indrani Pal, Anju A., H. Sreehari, Gitika Rameshan, C. S. Stalin
| Summary:
We carried out a uniform and systematic analysis of a sample of 112 nearby
bright Seyfert 1 type AGN, the observations of which were carried out by the
Nuclear Spectroscopic Telescope Array (NuSTAR) between August 2013 and May
2022. The main goal of this analysis is to investigate the nature of the X-ray
corona in Seyfert 1 galaxies. By fitting a physical model to the {it NuSTAR}
spectra, we were able to constrain the high-energy cut-off ($rm{E_{cut}}$) for
73 sources in our sample. To estimate the temperature of the corona
($rm{kT_{e}}$) in our sample of 112 sources, we used the Comptonization model
to fit their spectra. We could constrain $rm{kT_{e}}$ in 42 sources. We found
a strong positive correlation between $rm{E_{cut}}$ and $rm{kT_{e}}$ with
most of the sources lying above the empirical approximation of $rm{E_{cut}}$ =
2$-$3 $rm{kT_{e}}$. We investigated for possible correlations between various
properties of the corona obtained from physical model fits to the observed
spectra and between various coronal parameters and physical properties of the
sources such as Eddington ratio and black hole mass. We found (a) a strong
correlation between $rm{E_{cut}}$ and the photon index and (b) a significant
negative correlation between $rm{kT_{e}}$ and the optical depth. From detailed
statistical analysis of the correlation of coronal parameters with the
Eddington ratio and black hole mass, we found no significant correlation. The
correlations observed in this study indicate that an optically thin corona is
needed to sustain a hotter corona with a steeper spectrum.
| Search Query: ArXiv Query: search_query=au:”Claudio Ricci”&id_list=&start=0&max_results=3