The IXPE View of Neutron Star Low-Mass X-ray Binaries
F. Ursini, Andrea Gnarini, Fiamma Capitanio, Anna Bobrikova, M. Cocchi, Alessandro Di Marco, Sergio Fabiani, R. Farinelli, Fabio La Monaca, John Rankin, M. Lynne Saade, Juri Poutanen
Abstract
Low-mass X-ray binaries hosting weakly magnetized neutron stars (NS-LMXBs) are among the brightest sources in the X-ray sky. Since 2021, the Imaging X-ray Polarimetry Explorer (IXPE) has provided new measurements of the X-ray polarization of these sources. IXPE observations have revealed that most NS-LMXBs are significantly polarized in the X-rays, providing unprecedented insight into the geometry of their accretion flow. In this review paper, we summarize the first results obtained by IXPE on NS-LMXBs, the emerging trends within each class of sources (atoll/Z), and possible physical interpretations.