X-ray polarimetry of X-ray pulsar X Persei: another orthogonal rotator?

0574942 - ASÚ 2024 RIV US eng J - Článek v odborném periodiku
Mushtukov, A. A. - Tsygankov, S. S. - Poutanen, J. - Dovčiak, Michal - Karas, Vladimír … celkem 106 autorů
X-ray polarimetry of X-ray pulsar X Persei: another orthogonal rotator?
Monthly Notices of the Royal Astronomical Society. Roč. 524, č. 2 (2023), s. 2004-2014. ISSN 0035-8711. E-ISSN 1365-2966
Institucionální podpora: RVO:67985815
Klíčová slova: magnetic fields * polarization * neutron stars
Obor OECD: Astronomy (including astrophysics,space science)
Impakt faktor: 4.8, rok: 2022
Způsob publikování: Omezený přístup
https://doi.org/10.1093/mnras/stad1961

We present the results of observations X Persei performed with the Imaging X-ray Polarimetry Explorer (IXPE). The X-ray polarization signal was found to be strongly dependent on the spin phase of the pulsar. The energy-averaged polarization degree in 3-8 keV band varied from several to & SIM, 20 per cent over the pulse with a phase dependence resembling the pulse profile. The polarization angle shows significant variation and makes two complete revolutions during the pulse period, resulting in nearly nil pulse-phase averaged polarization. Applying the rotating vector model to the IXPE data we obtain the estimates for the rotation axis inclination and its position angle on the sky, as well as for the magnetic obliquity. The derived inclination is close to the orbital inclination, reported earlier for X Persei. The polarimetric data imply a large angle between the rotation and magnetic dipole axes, which is similar to the result reported recently for the X-ray pulsar GRO J1008-57. After eliminating the effect of polarization angle rotation over the pulsar phase using the best-fitting rotating vector model, the strong dependence of the polarization degree with energy was discovered, with its value increasing from 0 at & SIM, 2 keV to 30per cent at 8 keV.
Trvalý link: https://hdl.handle.net/11104/0345213