Polarization properties of weakly magnetized neutron stars in low-mass X-ray binaries. Issue 2 (2nd June 2022)

• Record Type: Journal Article
• Authors: Gnarini, A; Ursini, F; Matt, G; Bianchi, S; Capitanio, F; Cocchi, M; Farinelli, R; Zhang, W
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 514:Issue 2(2022)
• Page Start: 2561
• Page End: 2567
• Publication Date: 2022-06-02
• Subjects: accretion, accretion discs -- polarization -- stars: neutron -- X-rays: binaries; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac1523
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: X-ray polarimetry missions like Imaging X-ray Polarimetry Explorer will be able to measure for the first time the polarization properties of accreting, weakly magnetized neutron stars in low-mass X-ray binaries. In this work, we present simulations of the expected X-ray polarized signal, including the coronal emission for different geometries of the corona itself, i.e. a slab above the accretion disc and a spherical shell around the neutron star. The simulations are performed with the fully relativistic Monte Carlo code monk capable of computing the X-ray polarization degree and angle for various physical input parameters of the neutron star, disc, and corona. Different coronal geometries result in significantly different X-ray polarization properties, which can therefore be used to constrain the geometry of the systems.