Počet záznamů: 1
Complex variations in X-ray polarization in the X-ray pulsar LS V +44 17/RX J0440.9+4431
- 1.
SYSNO ASEP 0582492 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Complex variations in X-ray polarization in the X-ray pulsar LS V +44 17/RX J0440.9+4431 Tvůrce(i) Doroshenko, V. (DE)
Poutanen, J. (FI)
Heyl, J. (CA)
Dovčiak, Michal (ASU-R) RID, ORCID
Karas, Vladimír (ASU-R) RID, ORCIDCelkový počet autorů 112 Číslo článku A57 Zdroj.dok. Astronomy & Astrophysics. - : EDP Sciences - ISSN 0004-6361
Roč. 677, September (2023)Poč.str. 10 s. Forma vydání Online - E Jazyk dok. eng - angličtina Země vyd. FR - Francie Klíč. slova accretion disks ; magnetic fields ; X-rays binaries Obor OECD Astronomy (including astrophysics,space science) Způsob publikování Open access Institucionální podpora ASU-R - RVO:67985815 UT WOS 001162839200001 EID SCOPUS 85170824456 DOI 10.1051/0004-6361/202347088 Anotace We report on Imaging X-ray polarimetry explorer (IXPE) observations of the Be-transient X-ray pulsar LS V +44 17/RX J0440.9+4431 made at two luminosity levels during the giant outburst in January-February 2023. Considering the observed spectral variability and changes in the pulse profiles, the source was likely caught in supercritical and subcritical states with significantly different emission-region geometry, associated with the presence of accretion columns and hot spots, respectively. We focus here on the pulse-phase-resolved polarimetric analysis and find that the observed dependencies of the polarization degree and polarization angle (PA) on the pulse phase are indeed drastically different for the two observations. The observed differences, if interpreted within the framework of the rotating vector model (RVM), imply dramatic variations in the spin axis inclination, the position angle, and the magnetic colatitude by tens of degrees within the space of just a few days. We suggest that the apparent changes in the observed PA phase dependence are predominantly related to the presence of an unpulsed polarized component in addition to the polarized radiation associated with the pulsar itself. We then show that the observed PA phase dependence in both observations can be explained with a single set of RVM parameters defining the pulsar's geometry. We also suggest that the additional polarized component is likely produced by scattering of the pulsar radiation in the equatorial disk wind. Pracoviště Astronomický ústav Kontakt Radka Svašková, bibl@asu.cas.cz, Tel.: 323 620 326 Rok sběru 2024 Elektronická adresa https://hdl.handle.net/11104/0350554
Počet záznamů: 1