Association of Optical, Ultraviolet and Soft X-ray excess Emissions in AGNs

D. Nour; K. Sriram

doi:10.1093/mnras/stac3505

paper

Association of Optical, Ultraviolet and Soft X-ray excess Emissions in AGNs

arXiv:2211.15077 · doi:10.1093/mnras/stac3505

Abstract

Soft X-ray emission (0.5--2.0 keV) plays a pivotal role in regulating the optical and UV emission in the AGNs. We collected a sample of 1811 AGNs from the SDSS database and obtained various parameters of Balmer lines, optical continuum, MgII line \& UV continuum and studied their dependencies on soft X-ray luminosity. Based on the linear regression analysis, we found that FWHM $_{MgII}$ $\propto$ FWHM $_{H β}^{0.554}$ suggesting that UV emission is arising from a region relatively outside the broad line region (BLR) associated to the H $β$ emission and found a strong correlation between optical and UV luminosities (L $_{MgII}$ $\propto$ L $_{H β}^{0.822}$ ). It was noticed that the dependency of optical continuum luminosities on soft excess changes with the redshift (L $_{X}$ $\propto$ L $_{5100 A ˚}^{0.596}$ for z < 0.5 and L $_{X}$ $\propto$ L $_{5100 A ˚}^{0.429}$ for z > 0.5). The FWHM components of H $β$ and MgII core components were found to be virialized and is not affected by the soft excess emission whereas the wings of MgII display a dependency. We estimated a relation viz. L $_{X}$ $\propto$ L $_{3000 A ˚}^{0.520}$ FWHM $_{MgII}^{0.525}$ and found to be well in agreement with a proposed physical scenario. All the derived relations were used to understand the inter-modulating association of the BLR and disc in the AGNs.

arXiv comment13 pages, 16 figures, Accepted for publication in MNRAS

Association of Optical, Ultraviolet and Soft X-ray excess Emissions in AGNs

Abstract

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