Dramatic drop in the X-ray polarization of Swift J1727.8-1613 in the soft spectral state

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00586062" target="_blank" >RIV/67985815:_____/24:00586062 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/24:10494061

Výsledek na webu

<a href="https://hdl.handle.net/11104/0353686" target="_blank" >https://hdl.handle.net/11104/0353686</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/2041-8213/ad402e" target="_blank" >10.3847/2041-8213/ad402e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Dramatic drop in the X-ray polarization of Swift J1727.8-1613 in the soft spectral state

Popis výsledku v původním jazyce

Black hole X-ray binaries exhibit different spectral and timing properties in different accretion states. The X-ray outburst of a recently discovered and extraordinarily bright source, Swift J1727.8-1613, has enabled the first investigation of how the X-ray polarization properties of a source evolve with spectral state. The 2-8 keV polarization degree was previously measured by the Imaging X-ray Polarimetry Explorer (IXPE) to be approximate to 4% in the hard and hard intermediate states. Here we present new IXPE results taken in the soft state, with the X-ray flux dominated by the thermal accretion disk emission. We find that the polarization degree has dropped dramatically to less than or similar to 1%. This result indicates that the measured X-ray polarization is largely sensitive to the accretion state and the polarization fraction is significantly higher in the hard state when the X-ray emission is dominated by upscattered radiation in the X-ray corona. The combined polarization measurements in the soft and hard states disfavor a very high or low inclination of the system.

Název v anglickém jazyce

Dramatic drop in the X-ray polarization of Swift J1727.8-1613 in the soft spectral state

Popis výsledku anglicky

Black hole X-ray binaries exhibit different spectral and timing properties in different accretion states. The X-ray outburst of a recently discovered and extraordinarily bright source, Swift J1727.8-1613, has enabled the first investigation of how the X-ray polarization properties of a source evolve with spectral state. The 2-8 keV polarization degree was previously measured by the Imaging X-ray Polarimetry Explorer (IXPE) to be approximate to 4% in the hard and hard intermediate states. Here we present new IXPE results taken in the soft state, with the X-ray flux dominated by the thermal accretion disk emission. We find that the polarization degree has dropped dramatically to less than or similar to 1%. This result indicates that the measured X-ray polarization is largely sensitive to the accretion state and the polarization fraction is significantly higher in the hard state when the X-ray emission is dominated by upscattered radiation in the X-ray corona. The combined polarization measurements in the soft and hard states disfavor a very high or low inclination of the system.

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/GX21-06825X" target="_blank" >GX21-06825X: Akreující černé díry v nové éře polarizačních rentgenových misí</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Astrophysical Journal Letters

ISSN

2041-8205

e-ISSN

2041-8213

Svazek periodika

966

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

L35

Kód UT WoS článku

001215805800001

EID výsledku v databázi Scopus

2-s2.0-85193022270