Coronal Properties of Black Hole X-Ray Binaries in the Hard State as Seen by NuSTAR and Swift

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F20%3A00537272" target="_blank" >RIV/67985815:_____/20:00537272 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.3847/2041-8213/ab665e" target="_blank" >https://doi.org/10.3847/2041-8213/ab665e</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/2041-8213/ab665e" target="_blank" >10.3847/2041-8213/ab665e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Coronal Properties of Black Hole X-Ray Binaries in the Hard State as Seen by NuSTAR and Swift

Popis výsledku v původním jazyce

In this work we measure two important phenomenological parameters of corona (and hot accretion flow) in black hole X-ray binaries: the photon index “Gamma” and the electron temperature kTe. Thanks to the capability of the Nuclear Spectroscopic Telescope Array in hard X-rays, we measure these two parameters over six orders of magnitude in the 0.1-100 keV X-ray luminosity Lx, from 5.x.1038 erg s-1 down to as low as 5.x.1032 erg s-1. We confirm the existence of a “V”-shaped correlation between “Gamma” and Lx. Surprisingly, we observe a “Lambda” - shaped correlation between kTe and Lx. The cooler when brighter branch in the high-luminosity regime (Lx. 3.x.1036 erg s-1) agrees with previous results and can be understood under the existing model of Compton scattering in the corona. On the other hand, the apparent cooler when fainter (positive kTe-Lx correlation) branch in the low-luminosity regime (Lx. 3.x.1036 erg s-1) is unexpected, thus it puts a new challenge to existing models of hot accretion flow/corona.

Název v anglickém jazyce

Coronal Properties of Black Hole X-Ray Binaries in the Hard State as Seen by NuSTAR and Swift

Popis výsledku anglicky

In this work we measure two important phenomenological parameters of corona (and hot accretion flow) in black hole X-ray binaries: the photon index “Gamma” and the electron temperature kTe. Thanks to the capability of the Nuclear Spectroscopic Telescope Array in hard X-rays, we measure these two parameters over six orders of magnitude in the 0.1-100 keV X-ray luminosity Lx, from 5.x.1038 erg s-1 down to as low as 5.x.1032 erg s-1. We confirm the existence of a “V”-shaped correlation between “Gamma” and Lx. Surprisingly, we observe a “Lambda” - shaped correlation between kTe and Lx. The cooler when brighter branch in the high-luminosity regime (Lx. 3.x.1036 erg s-1) agrees with previous results and can be understood under the existing model of Compton scattering in the corona. On the other hand, the apparent cooler when fainter (positive kTe-Lx correlation) branch in the low-luminosity regime (Lx. 3.x.1036 erg s-1) is unexpected, thus it puts a new challenge to existing models of hot accretion flow/corona.

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

2020

Kód důvěrnosti údajů

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

Název periodika

Astrophysical Journal Letters

ISSN

2041-8213

e-ISSN

—

Svazek periodika

889

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

L18

Kód UT WoS článku

000520440200001

EID výsledku v databázi Scopus

2-s2.0-85080098338