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arXiv · 2303.12034

The first X-ray polarimetric observation of the black hole binary LMC X-1

Jakub Podgorny·Lorenzo Marra·Fabio Muleri·Nicole Rodriguez Cavero·Ajay Ratheesh·Michal Dovciak·Romana Mikusincova·Maimouna Brigitte·James F. Steiner·Alexandra Veledina·Stefano Bianchi·Henric Krawczynski·Jiri Svoboda·Philip Kaaret·Giorgio Matt·Javier A. Garcia·Pierre-Olivier Petrucci·Alexander A. Lutovinov·Andrey N. Semena·Alessandro Di Marco·Michela Negro·Martin C. Weisskopf·Adam Ingram·Juri Poutanen·Banfsheh Beheshtipour·Sohee Chun·Kun Hu·Tsunefumi Mizuno·Zhang Sixuan·Francesco Tombesi·Silvia Zane·Ivan Agudo·Lucio A. Antonelli·Matteo Bachetti·Luca Baldini·Wayne H. Baumgartner·Ronaldo Bellazzini·Stephen D. Bongiorno·Raffaella Bonino·Alessandro Brez·Niccolo Bucciantini·Fiamma Capitanio·Simone Castellano·Elisabetta Cavazzuti·Chien-Ting Chen·Stefano Ciprini·Enrico Costa·Alessandra De Rosa·Ettore Del Monte·Laura Di Gesu·Niccolo Di Lalla·Immacolata Donnarumma·Victor Doroshenko·Steven R. Ehlert·Teruaki Enoto·Yuri Evangelista·Sergio Fabiani·Riccardo Ferrazzoli·Shuichi Gunji·Kiyoshi Hayashida·Jeremy Heyl·Wataru Iwakiri·Svetlana G. Jorstad·Vladimir Karas·Fabian Kislat·Takao Kitaguchi·Jeffery J. Kolodziejczak·Fabio La Monaca·Luca Latronico·Ioannis Liodakis·Simone Maldera·Alberto Manfreda·Frederic Marin·Andrea Marinucci·Alan P. Marscher·Herman L. Marshall·Francesco Massaro·Ikuyuki Mitsuishi·Chi-Yung Ng·Stephen L. O'Dell·Nicola Omodei·Chiara Oppedisano·Alessandro Papitto·George G. Pavlov·Abel L. Peirson·Matteo Perri·Melissa Pesce-Rollins·Maura Pilia·Andrea Possenti·Simonetta Puccetti·Brian D. Ramsey·John Rankin·Oliver J. Roberts·Roger W. Romani·Carmelo Sgro·Patrick Slane·Paolo Soffitta·Gloria Spandre·Doug A. Swartz·Toru Tamagawa

Abstract

We report on an X-ray polarimetric observation of the high-mass X-ray binary LMC X-1 in the high/soft state, obtained by the Imaging X-ray Polarimetry Explorer (IXPE) in October 2022. The measured polarization is below the minimum detectable polarization of 1.1 per cent (at the 99 per cent confidence level). Simultaneously, the source was observed with the NICER, NuSTAR and SRG/ART-XC instruments, which enabled spectral decomposition into a dominant thermal component and a Comptonized one. The low 2-8 keV polarization of the source did not allow for strong constraints on the black-hole spin and inclination of the accretion disc. However, if the orbital inclination of about 36 degrees is assumed, then the upper limit is consistent with predictions for pure thermal emission from geometrically thin and optically thick discs. Assuming the polarization degree of the Comptonization component to be 0, 4, or 10 per cent, and oriented perpendicular to the polarization of the disc emission (in turn assumed to be perpendicular to the large scale ionization cone orientation detected in the optical band), an upper limit to the polarization of the disc emission of 1.0, 0.9 or 0.9 per cent, respectively, is found (at the 99 per cent confidence level).

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Jakub Podgorny, Lorenzo Marra, Fabio Muleri, Nicole Rodriguez Cavero, Ajay Ratheesh, Michal Dovciak, Romana Mikusincova, Maimouna Brigitte, James F. Steiner, Alexandra Veledina, Stefano Bianchi, Henric Krawczynski, Jiri Svoboda, Philip Kaaret, Giorgio Matt, Javier A. Garcia, Pierre-Olivier Petrucci, Alexander A. Lutovinov, Andrey N. Semena, Alessandro Di Marco, Michela Negro, Martin C. Weisskopf, Adam Ingram, Juri Poutanen, Banfsheh Beheshtipour, Sohee Chun, Kun Hu, Tsunefumi Mizuno, Zhang Sixuan, Francesco Tombesi, Silvia Zane, Ivan Agudo, Lucio A. Antonelli, Matteo Bachetti, Luca Baldini, Wayne H. Baumgartner, Ronaldo Bellazzini, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Niccolo Bucciantini, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Enrico Costa, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolo Di Lalla, Immacolata Donnarumma, Victor Doroshenko, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Riccardo Ferrazzoli, Shuichi Gunji, Kiyoshi Hayashida, Jeremy Heyl, Wataru Iwakiri, Svetlana G. Jorstad, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Frederic Marin, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Ikuyuki Mitsuishi, Chi-Yung Ng, Stephen L. O'Dell, Nicola Omodei, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Melissa Pesce-Rollins, Maura Pilia, Andrea Possenti, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Oliver J. Roberts, Roger W. Romani, Carmelo Sgro, Patrick Slane, Paolo Soffitta, Gloria Spandre, Doug A. Swartz, Toru Tamagawa. 2023-03-21. The first X-ray polarimetric observation of the black hole binary LMC X-1. https://arxiv.org/abs/2303.12034

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