Disk-jet coupling across the spectral transition in supermassive black holes

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Kang, Jia-Lai, Done, Chris, Hagen, Scott, Liao, Mai, Temple, Matthew J., Silverman, John D., Li, Junyao, Wang, Jun-Xian
Formato: Preprint
Publicado: 2025
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866912569877331968
author Kang, Jia-Lai
Done, Chris
Hagen, Scott
Liao, Mai
Temple, Matthew J.
Silverman, John D.
Li, Junyao
Wang, Jun-Xian
author_facet Kang, Jia-Lai
Done, Chris
Hagen, Scott
Liao, Mai
Temple, Matthew J.
Silverman, John D.
Li, Junyao
Wang, Jun-Xian
contents Accretion flows in both stellar and supermassive black holes show a distinct spectral transition. This is seen directly in binaries and changing look AGN, and also in a recent sample of eROSITA X-ray selected, unobscured AGN where the stacked spectral energy distributions (SEDs) for a single black hole mass bin (log $M/M_{\odot} =8-8.5$) clearly show the UV bright disk appearing as the luminosity increases. In binaries, this transition is associated with a change in radio jet, from coupling to the X-ray hot flow with $L_R \propto L_X^{0.7}$ (Fundamental Plane relation), to collapsing when the X-ray hot flow collapses into a disc. We explore the radio behaviour across the transition in our AGN sample by stacking VLASS images. We significantly detect weak radio emission even after subtracting the contribution from star formation in the host galaxy. The residual radio emission remains relatively constant across the transition, despite the mean mass accretion rate changing by a factor 6 and UV flux changing by a factor 100. However, the X-rays change by only a factor 2, giving a constant radio to X-ray flux ratio as predicted by the 'fundamental plane'. We show that this is consistent with these AGN having the same compact radio jet coupling to the X-ray hot flow (not the disc) as in the binaries. The most significant difference is the persistence of the coronal X-rays across the spectral transition in AGN, whereas in binaries the coronal X-rays can be very weak in the disc dominated state.
format Preprint
id arxiv_https___arxiv_org_abs_2504_08067
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Disk-jet coupling across the spectral transition in supermassive black holes
Kang, Jia-Lai
Done, Chris
Hagen, Scott
Liao, Mai
Temple, Matthew J.
Silverman, John D.
Li, Junyao
Wang, Jun-Xian
High Energy Astrophysical Phenomena
Astrophysics of Galaxies
Accretion flows in both stellar and supermassive black holes show a distinct spectral transition. This is seen directly in binaries and changing look AGN, and also in a recent sample of eROSITA X-ray selected, unobscured AGN where the stacked spectral energy distributions (SEDs) for a single black hole mass bin (log $M/M_{\odot} =8-8.5$) clearly show the UV bright disk appearing as the luminosity increases. In binaries, this transition is associated with a change in radio jet, from coupling to the X-ray hot flow with $L_R \propto L_X^{0.7}$ (Fundamental Plane relation), to collapsing when the X-ray hot flow collapses into a disc. We explore the radio behaviour across the transition in our AGN sample by stacking VLASS images. We significantly detect weak radio emission even after subtracting the contribution from star formation in the host galaxy. The residual radio emission remains relatively constant across the transition, despite the mean mass accretion rate changing by a factor 6 and UV flux changing by a factor 100. However, the X-rays change by only a factor 2, giving a constant radio to X-ray flux ratio as predicted by the 'fundamental plane'. We show that this is consistent with these AGN having the same compact radio jet coupling to the X-ray hot flow (not the disc) as in the binaries. The most significant difference is the persistence of the coronal X-rays across the spectral transition in AGN, whereas in binaries the coronal X-rays can be very weak in the disc dominated state.
title Disk-jet coupling across the spectral transition in supermassive black holes
topic High Energy Astrophysical Phenomena
Astrophysics of Galaxies
url https://arxiv.org/abs/2504.08067