| Name: Priyadarshee P. Dash |
| Affiliation: Physical Research Laboratory |
| Conference ID: ASI2026_379 |
| Title: Long-term Temporal and Spectral Analysis of Mrk 530 |
| Abstract Type: Poster |
| Abstract Category: High Energy Phenomena, Fundamental Physics and Astronomy |
| Author(s) and Co-Author(s) with Affiliation: Priyadarshee P. Dash(Physical Research Laboratory, Ahmedabad - 380009, India), Prantik Nandi(Indian Centre for Space Physics, Kolkata-700099, India), Sachindra Naik(Physical Research Laboratory, Ahmedabad - 380009, India), Narendranath Layek(Physical Research Laboratory, Ahmedabad - 380009, India), Sandip K. Chakrabarti(Indian Centre for Space Physics, Kolkata-700099, India) |
| Abstract: Active Galactic Nuclei (AGN) are highly luminous astronomical objects powered by the accretion of surrounding matter onto a Supermassive Black Hole (SMBH) via an accretion disk. The Optical/UV photons emitted by the thermal radiation of this disk undergo inverse Comptonization by a group of hot, relativistic electrons known as the corona, resulting in X-ray production. Recently, a comprehensive long-term multi-epoch X-ray spectral and temporal study was conducted on the AGN Mrk 530 over a period of 24 years (2001-2024) using data from the XMM-Newton and Swift observatories. Timing analysis revealed that the source exhibited largely consistent behaviour over shorter timescales (~10 ks). However, a long-term analysis conducted in 2018 identified a potential quasi-periodic variation in both the UV and X-ray bands, with consistent periods of approximately 90 days and 60 days, respectively. This modulation is likely attributed to the oscillation of the Comptonizing cloud caused by fluctuations in the accretion rate, which initially affects the outer UV-emitting regions and subsequently propagates on dynamical timescales to impact the inner X-ray-emitting regions. Long-term spectral analysis of Mrk 530 indicates significant variations in luminosity and photon index, as well as changes in the soft excess component, which is only detectable in the earlier epochs (2001-2006). Spectral modeling suggests that the soft excess component is due to the presence of an evolving warm corona with an electron temperature of ~0.2 keV. The significant variations observed in spectral parameters are attributed to changes in the mass accretion rate. Higher accretion rates are accompanied by a compact corona and softer spectra, while lower accretion rates correspond to an extended corona producing harder spectra. |
