BASS LIII: The Eddington Ratio as the Primary Regulator of the Fraction of X-ray Emission in Active Galactic Nuclei

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Gupta, Kriti Kamal, Ricci, Claudio, Tortosa, Alessia, Temple, Matthew J., Koss, Michael J., Trakhtenbrot, Benny, Bauer, Franz E., Treister, Ezequiel, Mushotzky, Richard, Kammoun, Elias, Papadakis, Iossif, Oh, Kyuseok, Rojas, Alejandra, Chang, Chin-Shin, Diaz, Yaherlyn, Jana, Arghajit, Kakkad, Darshan, del Moral-Castro, Ignacio, Peca, Alessandro, Powell, Meredith C., Stern, Daniel, Urry, C. Megan, Harrison, Fiona
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916847594504192
author Gupta, Kriti Kamal
Ricci, Claudio
Tortosa, Alessia
Temple, Matthew J.
Koss, Michael J.
Trakhtenbrot, Benny
Bauer, Franz E.
Treister, Ezequiel
Mushotzky, Richard
Kammoun, Elias
Papadakis, Iossif
Oh, Kyuseok
Rojas, Alejandra
Chang, Chin-Shin
Diaz, Yaherlyn
Jana, Arghajit
Kakkad, Darshan
del Moral-Castro, Ignacio
Peca, Alessandro
Powell, Meredith C.
Stern, Daniel
Urry, C. Megan
Harrison, Fiona
author_facet Gupta, Kriti Kamal
Ricci, Claudio
Tortosa, Alessia
Temple, Matthew J.
Koss, Michael J.
Trakhtenbrot, Benny
Bauer, Franz E.
Treister, Ezequiel
Mushotzky, Richard
Kammoun, Elias
Papadakis, Iossif
Oh, Kyuseok
Rojas, Alejandra
Chang, Chin-Shin
Diaz, Yaherlyn
Jana, Arghajit
Kakkad, Darshan
del Moral-Castro, Ignacio
Peca, Alessandro
Powell, Meredith C.
Stern, Daniel
Urry, C. Megan
Harrison, Fiona
contents Active galactic nuclei (AGN) emit radiation via accretion across the entire energy spectrum. While the standard disk and corona model can somewhat describe this emission, it fails to predict specific features such as the soft X-ray excess, the short-term optical/UV variability, and the observed UV/X-ray correlation in AGN. In this context, the fraction of AGN emission in different bands (i.e., bolometric corrections) can be useful to better understand the accretion physics of AGN. Past studies have shown that the X-ray bolometric corrections are strongly dependent on the physical properties of AGN, such as their luminosities and Eddington ratios. However, since these two parameters depend on each other, it has been unclear which is the main driver of the X-ray bolometric corrections. We present here results from a large study of hard X-ray-selected (14-195 keV) nearby ($z<0.1$) AGN. Based on our systematic analysis of the simultaneous optical-to-X-ray spectral energy distributions of 236 unobscured AGN, we found that the primary parameter controlling the X-ray bolometric corrections is the Eddington ratio. Our results show that while the X-ray bolometric correction increases with the bolometric luminosity for sources with intermediate Eddington ratios ($0.01-1$), this dependence vanishes for sources with lower Eddington ratios ($<0.01$). This could be used as evidence for a change in the accretion physics of AGN at low Eddington ratios.
format Preprint
id arxiv_https___arxiv_org_abs_2507_12541
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle BASS LIII: The Eddington Ratio as the Primary Regulator of the Fraction of X-ray Emission in Active Galactic Nuclei
Gupta, Kriti Kamal
Ricci, Claudio
Tortosa, Alessia
Temple, Matthew J.
Koss, Michael J.
Trakhtenbrot, Benny
Bauer, Franz E.
Treister, Ezequiel
Mushotzky, Richard
Kammoun, Elias
Papadakis, Iossif
Oh, Kyuseok
Rojas, Alejandra
Chang, Chin-Shin
Diaz, Yaherlyn
Jana, Arghajit
Kakkad, Darshan
del Moral-Castro, Ignacio
Peca, Alessandro
Powell, Meredith C.
Stern, Daniel
Urry, C. Megan
Harrison, Fiona
Astrophysics of Galaxies
High Energy Astrophysical Phenomena
Active galactic nuclei (AGN) emit radiation via accretion across the entire energy spectrum. While the standard disk and corona model can somewhat describe this emission, it fails to predict specific features such as the soft X-ray excess, the short-term optical/UV variability, and the observed UV/X-ray correlation in AGN. In this context, the fraction of AGN emission in different bands (i.e., bolometric corrections) can be useful to better understand the accretion physics of AGN. Past studies have shown that the X-ray bolometric corrections are strongly dependent on the physical properties of AGN, such as their luminosities and Eddington ratios. However, since these two parameters depend on each other, it has been unclear which is the main driver of the X-ray bolometric corrections. We present here results from a large study of hard X-ray-selected (14-195 keV) nearby ($z<0.1$) AGN. Based on our systematic analysis of the simultaneous optical-to-X-ray spectral energy distributions of 236 unobscured AGN, we found that the primary parameter controlling the X-ray bolometric corrections is the Eddington ratio. Our results show that while the X-ray bolometric correction increases with the bolometric luminosity for sources with intermediate Eddington ratios ($0.01-1$), this dependence vanishes for sources with lower Eddington ratios ($<0.01$). This could be used as evidence for a change in the accretion physics of AGN at low Eddington ratios.
title BASS LIII: The Eddington Ratio as the Primary Regulator of the Fraction of X-ray Emission in Active Galactic Nuclei
topic Astrophysics of Galaxies
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2507.12541