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

Result code in 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>

Result on the web

<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>

Result language

angličtina

Original language name

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

Original language description

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.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10308 - Astronomy (including astrophysics,space science)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2024

Confidentiality

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

Name of the periodical

Astrophysical Journal Letters

ISSN

2041-8205

e-ISSN

2041-8213

Volume of the periodical

960

Issue of the periodical within the volume

2

Country of publishing house

US - UNITED STATES

Number of pages

15

Pages from-to

L11

UT code for WoS article

001137090300001

EID of the result in the Scopus database

2-s2.0-85182388102