| Abstract : | Active galactic nuclei (AGN) are extremely luminous objects showing variable emissions at all observed wavelengths. We study the nearby (z=0.035291) narrow-line Seyfert 1 (NLS1) galaxy Mrk 110, which is highly variable in the optical/UV bands. The source has been monitored with XMM-Newton, AstroSat, and NuSTAR since 2004. Using these long-term multi-wavelength observations, we probe the evolution of accretion disc and corona components in the source by investigating the spectral and temporal variability of the optical, UV, and X-ray emissions. From AstroSat observations, we find UV and hard X-ray (2-10 keV) flux variability in the source over time scales of weeks. The spectral analysis of the NuSTAR data clearly shows the presence of relativistic X-ray reflection in Mrk 110 in the hard X-ray band. In the soft X-ray regime, evidence of excess emission, known as the "soft X-ray excess", has been observed at all epochs of XMM-Newton and AstroSat observations. We investigate the origin and variability of soft excess in the source by modelling the multi-epoch broadband X-ray spectra with double Comptonisation and reflection models. The optical to X-ray SED analysis helps us understand the disc-corona geometry and the truncation accretion disc, which provides more insights into a potential changing-look scenario related to the accretion rate fluctuations. |
