Highly significant detection of X-ray polarization from the brightest accreting neutron star Sco X-1

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985815%3A_____%2F24%3A00581831" target="_blank" >RIV/67985815:_____/24:00581831 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0353285" target="_blank" >https://hdl.handle.net/11104/0353285</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/2041-8213/ad132d" target="_blank" >10.3847/2041-8213/ad132d</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Highly significant detection of X-ray polarization from the brightest accreting neutron star Sco X-1

Popis výsledku v původním jazyce

The Imaging X-ray Polarimetry Explorer measured with high significance the X-ray polarization of the brightest Z-source, Sco X-1, resulting in the nominal 2-8 keV energy band in a polarization degree of 1.0% +/- 0.2% and a polarization angle of 8(degrees) +/- 6(degrees) at a 90% confidence level. This observation was strictly simultaneous with observations performed by NICER, NuSTAR, and Insight-HXMT, which allowed for a precise characterization of its broadband spectrum from soft to hard X-rays. The source has been observed mainly in its soft state, with short periods of flaring. We also observed low-frequency quasiperiodic oscillations. From a spectropolarimetric analysis, we associate a polarization to the accretion disk at <3.2% at 90% confidence level, compatible with expectations for an electron scattering dominated optically thick atmosphere at the Sco X-1 inclination of similar to 44(degrees), for the higher-energy Comptonized component, we obtain a polarization of 1.3% +/- 0.4%, in agreement with expectations for a slab of Thomson optical depth of similar to 7 and an electron temperature of similar to 3 keV. A polarization rotation with respect to previous observations by OSO-8 and PolarLight, and also with respect to the radio-jet position angle, is observed. This result may indicate a variation of the polarization with the source state that can be related to relativistic precession or a change in the corona geometry with the accretion flow.

Název v anglickém jazyce

Highly significant detection of X-ray polarization from the brightest accreting neutron star Sco X-1

Popis výsledku anglicky

The Imaging X-ray Polarimetry Explorer measured with high significance the X-ray polarization of the brightest Z-source, Sco X-1, resulting in the nominal 2-8 keV energy band in a polarization degree of 1.0% +/- 0.2% and a polarization angle of 8(degrees) +/- 6(degrees) at a 90% confidence level. This observation was strictly simultaneous with observations performed by NICER, NuSTAR, and Insight-HXMT, which allowed for a precise characterization of its broadband spectrum from soft to hard X-rays. The source has been observed mainly in its soft state, with short periods of flaring. We also observed low-frequency quasiperiodic oscillations. From a spectropolarimetric analysis, we associate a polarization to the accretion disk at <3.2% at 90% confidence level, compatible with expectations for an electron scattering dominated optically thick atmosphere at the Sco X-1 inclination of similar to 44(degrees), for the higher-energy Comptonized component, we obtain a polarization of 1.3% +/- 0.4%, in agreement with expectations for a slab of Thomson optical depth of similar to 7 and an electron temperature of similar to 3 keV. A polarization rotation with respect to previous observations by OSO-8 and PolarLight, and also with respect to the radio-jet position angle, is observed. This result may indicate a variation of the polarization with the source state that can be related to relativistic precession or a change in the corona geometry with the accretion flow.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

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

960

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

L11

Kód UT WoS článku

001137090300001

EID výsledku v databázi Scopus

2-s2.0-85182388102