Speaker
Description
We present the first X-ray polarimetric measurement of the eclipsing neutron star low-mass X-ray binary system AX J1745.6-2901 obtained with the Imaging X-ray Polarimetry Explorer (IXPE). This transient source lies within ∼1.5′ of the Galactic center and was observed serendipitously during a 150 ks IXPE pointing at MAXI J1744-294. The crowded and highly absorbed Galactic center environment makes polarization measurements particularly challenging, requiring a careful assessment of contamination from the primary target and the surrounding diffuse emission.
We detect a polarization degree of PD = 14.7% ± 4.0% and a polarization angle of PA = 122◦ ± 8◦. Phase-resolved analysis reveals a significant increase in polarization during the eclipse and dip phase, reaching PD = 34.2% ± 8.7%. The enhanced polarization when the central X-ray source is obscured indicates that scattering processes dominate the polarized emission, likely originating in an equatorial disk wind or extended reprocessing structure. These results provide new constraints on the geometry of high-inclination accreting neutron star systems and demonstrate the diagnostic power of X-ray polarimetry for probing accretion physics in complex Galactic center environments.