The First X-Ray Polarimetry of an Eclipsing Low-Mass X-Ray Binary: Serendipitous IXPE Observation of AX J1745.6-2901

Romana Mikušincová; Lorenzo Marra; Hemanth Manikantan; Stefano Bianchi; Fiamma Capitanio; Sudip Chakraborty; Raul Ciancarella; Enrico Costa; Nicolas De Angelis; Melania Del Santo; Sergio Fabiani; Riccardo Ferrazzoli; Vittoria E. Gianolli; Andrea Gnarini; Adam Ingram; Shifra Mandel; Guglielmo Mastroserio; Giorgio Matt; Kaya Mori; Fabio Muleri; Simone Pagliarella; Maxime Parra; P. O. Petrucci; Jakub Podgorný; Juri Poutanen; Swati Ravi; Paolo Soffitta; James F. Steiner; Antonella Tarana; Roberto Taverna; Francesco Ursini; Alexandra Veledina; Federico M. Vincentelli; Anastasiya Yilmaz; Barbara De Marco; Maitrayee Gupta; Vladislav Loktev; Thomas D. Russell; Jiří Svoboda; Francesco Tombesi; Shuo Zhang

arXiv · 2512.13182

The First X-Ray Polarimetry of an Eclipsing Low-Mass X-Ray Binary: Serendipitous IXPE Observation of AX J1745.6-2901

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Abstract

We present the first X-ray polarimetric measurement of the neutron star low-mass X-ray binary system AX J1745.6-2901 conducted by the Imaging X-ray Polarimetry Explorer (IXPE) satellite. This transient source, located within $ \sim $1.5' of the Galactic center, was observed serendipitously during a MAXI J1744-294 observation with a duration of 150 ks. The complex nature of the region in which AX J1745.6-2901 is located poses a challenge for studying its polarization. By performing a detailed analysis of the contamination from MAXI J1744-294 and the Galactic center diffuse emission, we find the source polarization degree PD = 14.7$\% \pm$ 4.0$\%$ and polarization angle PA = 122$^\circ \pm 8^\circ$. The phase-resolved analysis shows increase in polarization during the eclipse phase, with PD = 34.2$\% \pm$ 8.7$\%$, suggesting that the polarization-inducing mechanisms are of scattering nature, probably originating from disk winds.

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Romana Mikušincová, Lorenzo Marra, Hemanth Manikantan, Stefano Bianchi, Fiamma Capitanio, Sudip Chakraborty, Raul Ciancarella, Enrico Costa, Nicolas De Angelis, Melania Del Santo, Sergio Fabiani, Riccardo Ferrazzoli, Vittoria E. Gianolli, Andrea Gnarini, Adam Ingram, Shifra Mandel, Guglielmo Mastroserio, Giorgio Matt, Kaya Mori, Fabio Muleri, Simone Pagliarella, Maxime Parra, P. O. Petrucci, Jakub Podgorný, Juri Poutanen, Swati Ravi, Paolo Soffitta, James F. Steiner, Antonella Tarana, Roberto Taverna, Francesco Ursini, Alexandra Veledina, Federico M. Vincentelli, Anastasiya Yilmaz, Barbara De Marco, Maitrayee Gupta, Vladislav Loktev, Thomas D. Russell, Jiří Svoboda, Francesco Tombesi, Shuo Zhang. 2025-12-15. The First X-Ray Polarimetry of an Eclipsing Low-Mass X-Ray Binary: Serendipitous IXPE Observation of AX J1745.6-2901. https://arxiv.org/abs/2512.13182

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