A Physical Model for the UV/Optical Power Spectra of AGN

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F22%3A00560484" target="_blank" >RIV/67985815:_____/22:00560484 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0334214" target="_blank" >https://hdl.handle.net/11104/0334214</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ac7e4d" target="_blank" >10.3847/1538-4357/ac7e4d</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A Physical Model for the UV/Optical Power Spectra of AGN

Popis výsledku v původním jazyce

The UV/optical variability of active galactic nuclei (AGN) has long been thought to be driven by the X-ray illumination of the accretion disk. However, recent multiwavelength campaigns of nearby Seyfert galaxies seem to challenge this paradigm, with an apparent discrepancy between observations and the underlying theory. In order to further probe the connection between the UV/optical and X-ray variability in AGN, we developed a physical model to reproduce the UV/optical power spectral densities (PSDs) of AGN assuming the thermal reprocessing of the X-rays in the disk. This model offers a novel way to probe the innermost regions of AGN. We use our model to study the variability of NGC 5548, and we infer that the X-ray and UV/optical PSDs as well as the interband UV/optical time lags are all well reproduced. We also derive constraints on the source physical parameters, such as the X-ray corona height and the accretion rate. Our results suggest that X-ray disk reprocessing accounts for the full variability properties of this AGN, within the considered timescales. Using earlier data of NGC 5548, we also show that our model can reproduce its PSD in different epochs, establishing the feasibility of using PSD modeling to investigate the time evolution of a source.

Název v anglickém jazyce

A Physical Model for the UV/Optical Power Spectra of AGN

Popis výsledku anglicky

The UV/optical variability of active galactic nuclei (AGN) has long been thought to be driven by the X-ray illumination of the accretion disk. However, recent multiwavelength campaigns of nearby Seyfert galaxies seem to challenge this paradigm, with an apparent discrepancy between observations and the underlying theory. In order to further probe the connection between the UV/optical and X-ray variability in AGN, we developed a physical model to reproduce the UV/optical power spectral densities (PSDs) of AGN assuming the thermal reprocessing of the X-rays in the disk. This model offers a novel way to probe the innermost regions of AGN. We use our model to study the variability of NGC 5548, and we infer that the X-ray and UV/optical PSDs as well as the interband UV/optical time lags are all well reproduced. We also derive constraints on the source physical parameters, such as the X-ray corona height and the accretion rate. Our results suggest that X-ray disk reprocessing accounts for the full variability properties of this AGN, within the considered timescales. Using earlier data of NGC 5548, we also show that our model can reproduce its PSD in different epochs, establishing the feasibility of using PSD modeling to investigate the time evolution of a source.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Svazek periodika

935

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

18

Strana od-do

93

Kód UT WoS článku

000841985700001

EID výsledku v databázi Scopus

2-s2.0-85136670421