First X-ray polarization measurement confirms the low black-hole spin in LMC X-3
Creators: name: Svoboda, Jiří
name: Dovčiak, Michal
name: Steiner, James F.
name: Muleri, Fabio
name: Ingram, Adam
name: Yilmaz, Anastasiya
name: Cavero, Nicole Rodriguez
name: Marra, Lorenzo
name: Poutanen, Juri
name: Veledina, Alexandra
name: Mojaver, Mehrnoosh Rahbardar
name: Bianchi, Stefano
name: Garcia, Javier
name: Kaaret, Philip
name: Krawczynski, Henric
name: Matt, Giorgio
name: Podgorný, Jakub
name: Weisskopf, Martin C.
name: Kislat, Fabian
name: Petrucci, Pierre-Olivier
name: Brigitte, Maimouna
name: Bursa, Michal
name: Fabiani, Sergio
name: Hu, Kun
name: Chun, Sohee
name: Mastroserio, Guglielmo
name: Mikušincová, Romana
name: Ratheesh, Ajay
name: Romani, Roger W.
name: Soffitta, Paolo
name: Ursini, Francesco
name: Zane, Silvia
name: Agudo, Iván
name: Antonelli, Lucio A.
name: Bachetti, Matteo
name: Baldini, Luca
name: Baumgartner, Wayne H.
name: Bellazzini, Ronaldo
name: Bongiorno, Stephen D.
name: Bonino, Raffaella
name: Brez, Alessandro
name: Bucciantini, Niccolo
name: Capitanio, Fiamma
name: Castellano, Simone
name: Cavazzuti, Elisabetta
name: Chen, Chien-Ting
name: Ciprini, Stefano
name: Costa, Enrico
name: De Rosa, Alessandra
name: Del Monte, Ettore
name: Di Gesu, Laura
name: Di Lalla, Niccolo
name: Di Marco, Alessandro
name: Donnarumma, Immacolata
name: Doroshenko, Victor
name: Ehlert, Steven
name: Enoto, Teruaki
name: Evangelista, Yuri
name: Ferrazzoli, Riccardo
name: Gunji, Shuichi
name: Hayashida, Kiyoshi
name: Heyl, Jeremy
name: Iwakiri, Wataru
name: Jorstad, Svetlana G.
name: Karas, Vladimír
name: Kitaguchi, Takao
name: Kolodziejczak, Jeffery
name: La Monaca, Fabio
name: Latronico, Luca
name: Liodakis, Ioannis
name: Maldera, Simone
name: Manfreda, Alberto
name: Marin, Frédéric
name: Marinucci, Andrea
name: Marscher, Alan P.
name: Marshall, Herman L.
name: Massaro, Francesco
name: Mitsuishi, Ikuyuki
name: Mizuno, Tsunefumi
name: Negro, Michela
name: Ng, C. -Y.
name: O'Dell, Stephen L.
name: Omodei, Nicola
name: Oppedisano, Chiara
name: Papitto, Alessandro
name: Pavlov, George
name: Peirson, Abel
name: Perri, Matteo
name: Pesce-Rollins, Melissa
name: Pilia, Maura
name: Possenti, Andrea
name: Puccetti, Simonetta
name: Ramsey, Brian D.
name: Rankin, John
name: Roberts, Oliver
name: Sgro, Carmelo
name: Slane, Patrick
name: Spandre, Gloria
name: Swartz, Douglas A.
name: Tamagawa, Toru
name: Tavecchio, Fabrizio
name: Taverna, Roberto
name: Tawara, Yuzuru
name: Tennant, Allyn F.
name: Thomas, Nicholas E.
name: Tombesi, Francesco
name: Trois, Alessio
name: Tsygankov, Sergey S.
name: Turolla, Roberto
name: Vink, Jacco
name: Wu, Kinwah
name: Xie, Fei
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: X-ray polarization is a powerful tool to investigate the geometry of accreting material around black holes, allowing independent measurements of the black hole spin and orientation of the innermost parts of the accretion disk. We perform the X-ray spectro-polarimetric analysis of an X-ray binary system in the Large Magellanic Cloud, LMC X-3, that hosts a stellar-mass black hole, known to be persistently accreting since its discovery. We report the first detection of the X-ray polarization in LMC X-3 with the Imaging X-ray Polarimetry Explorer, and find the average polarization degree of 3.2% +- 0.6% and a constant polarization angle -42 deg +- 6 deg over the 2-8 keV range. Using accompanying spectroscopic observations by NICER, NuSTAR, and the Neil Gehrels Swift observatories, we confirm previous measurements of the black hole spin via the X-ray continuum method, a ~ 0.2. From polarization analysis only, we found consistent results with low black-hole spin, with an upper limit of a &lt; 0.7 at a 90% confidence level. A slight increase of the polarization degree with energy, similar to other black-hole X-ray binaries in the soft state, is suggested from the data but with a low statistical significance.
description: 14 pages, 8 figures, submitted to ApJ