A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Evidence for a Black Hole Spin-Orbit Misalignment in the X-Ray Binary Cyg X-1
Tekijät: Zdziarski Andrzej A., Veledina Alexandra, Szanecki Michał, Green David A., Bright Joe S., Williams David R. A.
Kustantaja: IOP Publishing Ltd
Julkaisuvuosi: 2023
Journal: Astrophysical Journal Letters
Tietokannassa oleva lehden nimi: ASTROPHYSICAL JOURNAL LETTERS
Lehden akronyymi: ASTROPHYS J LETT
Artikkelin numero: L45
Vuosikerta: 951
Numero: 2
Sivujen määrä: 8
ISSN: 2041-8205
eISSN: 2041-8213
DOI: https://doi.org/10.3847/2041-8213/ace2c9
Verkko-osoite: https://doi.org/10.3847/2041-8213/ace2c9
Rinnakkaistallenteen osoite: https://research.utu.fi/converis/portal/detail/Publication/180462039
Recently, the accretion geometry of the black hole X-ray binary Cyg X-1 was probed with the X-ray polarization. The position angle of the X-ray-emitting flow was found to be aligned with the position angle of the radio jet in the plane of the sky. At the same time, the observed high polarization degree could be obtained only for a high inclination of the X-ray-emitting flow, indicating a misalignment between the binary axis and the black hole spin. The jet, in turn, is believed to be directed by the spin axis; hence, a similar misalignment is expected between the jet and binary axes. We test this hypothesis using very long (up to about 26 yr) multiband radio observations. We find a misalignment of 20°–30°. However, contrary to the earlier expectations, the jet and binary viewing angles are found to be similar, while the misalignment is seen between the position angles of the jet and the binary axis on the plane of the sky. Furthermore, the presence of the misalignment calls into question our understanding of the evolution of this binary system.
Ladattava julkaisu This is an electronic reprint of the original article. |