Exploring MAXI J1744-294: IXPE insights into a Newly Discovered X-ray Transient

Lorenzo Marra; Romana Mikušincová; Federico M. Vincentelli; Fiamma Capitanio; Melania Del Santo; Sergio Fabiani; Shifra Mandel; Fabio Muleri; Maxime Parra; Paolo Soffitta; Antonella Tarana; M. Cristina Baglio; Stefano Bianchi; Enrico Costa; Antonino D'Aì; Barbara De Marco; Michal Dovčiak; Vittoria Elvezia Gianolli; Andrea Gnarini; Maitrayee Gupta; Adam Ingram; Guglielmo Mastroserio; Giorgio Matt; Kaya Mori; Pierre-Olivier Petrucci; Jakub Podgorný; Juri Poutanen; James F. Steiner; Jiří Svoboda; Roberto Taverna; Francesco Tombesi; Swati Ravi; Jérôme Rodriguez; Thomas D. Russell; Alexandra Veledina; Shuo Zhang

arXiv · 2506.17050

Exploring MAXI J1744-294: IXPE insights into a Newly Discovered X-ray Transient

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Abstract

We present the first IXPE spectro-polarimetric observation of the black hole candidate MAXI J1744$-$294, a transient X-ray source discovered during a bright 2025 outburst in the Galactic center region. During the $\sim$150 ks observation, the source was found in the soft state, and its spectrum was well described by an absorbed multicolor disk with a minor high-energy tail. No significant polarization was detected, and we derived a 3$σ$ upper limit on the polarization degree of $1.3\%$ in the 2--8 keV energy band. This result is consistent with previous findings for soft-state black hole binaries observed at low to intermediate inclination angles. By comparing the polarization degree upper limit with theoretical predictions for standard accretion disk emission, we constrain the disk inclination to $i \lesssim 38^\circ$--$71^\circ$, depending on the black hole spin and the disk atmosphere albedo.

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Lorenzo Marra, Romana Mikušincová, Federico M. Vincentelli, Fiamma Capitanio, Melania Del Santo, Sergio Fabiani, Shifra Mandel, Fabio Muleri, Maxime Parra, Paolo Soffitta, Antonella Tarana, M. Cristina Baglio, Stefano Bianchi, Enrico Costa, Antonino D'Aì, Barbara De Marco, Michal Dovčiak, Vittoria Elvezia Gianolli, Andrea Gnarini, Maitrayee Gupta, Adam Ingram, Guglielmo Mastroserio, Giorgio Matt, Kaya Mori, Pierre-Olivier Petrucci, Jakub Podgorný, Juri Poutanen, James F. Steiner, Jiří Svoboda, Roberto Taverna, Francesco Tombesi, Swati Ravi, Jérôme Rodriguez, Thomas D. Russell, Alexandra Veledina, Shuo Zhang. 2025-06-20. Exploring MAXI J1744-294: IXPE insights into a Newly Discovered X-ray Transient. https://arxiv.org/abs/2506.17050

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