X-Ray Polarization of the Black Hole X-Ray Binary 4U 1630-47 Challenges the Standard Thin Accretion Disk Scenario

0585062 - ASÚ 2025 RIV GB eng J - Journal Article
Ratheesh, A. - Dovčiak, Michal - Krawczynski, H.S. - Podgorný, Jakub - Svoboda, Jiří - Karas, Vladimír … Total 115 authors
X-Ray Polarization of the Black Hole X-Ray Binary 4U 1630-47 Challenges the Standard Thin Accretion Disk Scenario.
Astrophysical Journal. Roč. 964, č. 1 (2024), č. článku 77. ISSN 0004-637X. E-ISSN 1538-4357
R&D Projects: GA ČR(CZ) GX21-06825X
Institutional support: RVO:67985815
Keywords : polarimetry * X-ray astronomy * stellar mass black holes
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 4.9, year: 2022
Method of publishing: Open access

A large energy-dependent X-ray polarization degree is detected by the Imaging X-ray Polarimetry Explorer (IXPE) in the high-soft emission state of the black hole X-ray binary 4U 1630-47. The highly significant detection (at approximate to 50 sigma confidence level) of an unexpectedly high polarization, rising from similar to 6% at 2 keV to similar to 10% at 8 keV, cannot be easily reconciled with standard models of thin accretion disks. In this work, we compare the predictions of different theoretical models with the IXPE data and conclude that the observed polarization properties are compatible with a scenario in which matter accretes onto the black hole through a thin disk covered by a partially ionized atmosphere flowing away at mildly relativistic velocities.
Permanent Link: https://hdl.handle.net/11104/0353543