Constraining the Size of the Corona with Fully Relativistic Calculations of Spectra of Extended Coronae. I. The Monte Carlo Radiative Transfer Code

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F19%3A00519777" target="_blank" >RIV/67985815:_____/19:00519777 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.3847/1538-4357/ab1261" target="_blank" >https://doi.org/10.3847/1538-4357/ab1261</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ab1261" target="_blank" >10.3847/1538-4357/ab1261</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Constraining the Size of the Corona with Fully Relativistic Calculations of Spectra of Extended Coronae. I. The Monte Carlo Radiative Transfer Code

Popis výsledku v původním jazyce

The size and geometry of the X-ray-emitting corona in an active galactic nucleus (AGN) are still not well constrained. Dovciak & Done proposed a method based on calculations assuming a point-like lamp-post corona. To perform more self-consistent calculations of energy spectra of extended coronae, we develop MONK, a Monte Carlo radiative transfer code dedicated to calculations of Comptonized spectra in the Kerr spacetime. In MONK we assume a Klein-Nishina scattering cross section and include all general relativistic effects. We find that for a corona located above the disk, the spectrum is not isotropic, but has harder and less luminous spectra toward observers at lower inclinations, owing to anisotropic illumination of the seed photons. This anisotropy also leads to an underestimated size for the corona if we assume it to be a point-like, isotropic source located on the rotation axis of the black hole, demonstrating the necessity for more self-consistent calculations. We also study the effect of motion and geometry of the corona on the emergent spectrum. Finally, we discuss the implication of anisotropic coronal emission for the reflection spectrum in AGNs as well as black hole X-ray binaries (BHXRBs). We find that by assuming the coronal emission to be isotropic, one may underestimate the soft excess in AGNs, and the reflection continuum and iron K fluorescent line flux in BHXRBs.

Název v anglickém jazyce

Constraining the Size of the Corona with Fully Relativistic Calculations of Spectra of Extended Coronae. I. The Monte Carlo Radiative Transfer Code

Popis výsledku anglicky

The size and geometry of the X-ray-emitting corona in an active galactic nucleus (AGN) are still not well constrained. Dovciak & Done proposed a method based on calculations assuming a point-like lamp-post corona. To perform more self-consistent calculations of energy spectra of extended coronae, we develop MONK, a Monte Carlo radiative transfer code dedicated to calculations of Comptonized spectra in the Kerr spacetime. In MONK we assume a Klein-Nishina scattering cross section and include all general relativistic effects. We find that for a corona located above the disk, the spectrum is not isotropic, but has harder and less luminous spectra toward observers at lower inclinations, owing to anisotropic illumination of the seed photons. This anisotropy also leads to an underestimated size for the corona if we assume it to be a point-like, isotropic source located on the rotation axis of the black hole, demonstrating the necessity for more self-consistent calculations. We also study the effect of motion and geometry of the corona on the emergent spectrum. Finally, we discuss the implication of anisotropic coronal emission for the reflection spectrum in AGNs as well as black hole X-ray binaries (BHXRBs). We find that by assuming the coronal emission to be isotropic, one may underestimate the soft excess in AGNs, and the reflection continuum and iron K fluorescent line flux in BHXRBs.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

<a href="/cs/project/GA17-02430S" target="_blank" >GA17-02430S: Geometrické vlastnosti korony akrečního disku v aktivních galaktických jádrech</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Astrophysical Journal

ISSN

1538-4357

e-ISSN

—

Svazek periodika

875

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

13

Strana od-do

148

Kód UT WoS článku

000465974900017

EID výsledku v databázi Scopus

2-s2.0-85067185682