| Name: Ritik Kumar |
| Affiliation: Indian Institute of Science, Bengaluru |
| Conference ID: ASI2026_241 |
| Title: Nature of corona in few bright AGN |
| Abstract Type: Poster |
| Abstract Category: Galaxies and Cosmology |
| Author(s) and Co-Author(s) with Affiliation: Ritik Kumar(Indian Institute of Science, Bangalore - 560012, India), C S Stalin(Indian Institute of Astrophysics, Bangalore - 560034, India), Jyotishree Hota(Indian Institute of Astrophysics, Bangalore - 560034, India) |
| Abstract: Active galactic nuclei (AGN) are luminous extragalactic sources powered by the accretion of
matter onto supermassive black holes at the centre of galaxies.
They emit across the entire electromagnetic spectrum with particularly strong emission
in the X-ray band. The X-ray emission in the radio-quiet category of AGN is believed
to be produced by inverse Compton scattering of UV seed photons from the accretion
disk by a population of hot electrons is a compact region known as corona,
situated close to the disk. The resulting X-ray spectrum is well described by
a power law shape upto a high cut-off energy cut-off beyond which the spectrum
steepens. This cut-off energy is directly related to the temperature of the
corona. In this work, we aim to characterise the temperature of the corona,
examine its variation if any and investigate correlations if any between between
coronal temperature and the physical properties of the sources. For this we
carried out systematic investigation of a sample of four AGN with multiple
epochs of observations from NuSTAR, amounting to a total of 35 epochs.
Both phenomenological and physically motivated model fits were carried out on the NuSTAR data
to infer the temperature of the corona and other properties of the sources. Our
analysis indicates that the temperature of the corona in our sample remains relatively stable
during the epochs of observations analysed here. The detailed results of this
study will be presented at the meeting. |
