Title: | The First X-Ray Polarization Observation of the Black Hole X-Ray Binary 4U 1630-47 in the Steep Power-law State |
Authors: | Rodriguez Cavero, Nicole MARRA, Lorenzo Krawczynski, Henric Dovčiak, Michal Bianchi, Stefano Steiner, James F. Svoboda, Jiri CAPITANIO, FIAMMA Matt, Giorgio Negro, Michela Ingram, Adam Tennant, Allyn F. Thomas, Nicholas E. TOMBESI, Francesco TROIS, ALESSIO Tsygankov, Sergey S. Turolla, Roberto Vink, Jacco Weisskopf, Martin C. Wu, Kinwah XIE, FEI Veledina, Alexandra Taverna, Roberto Karas, Vladimir Ursini, Francesco Podgorný, Jakub RATHEESH, AJAY Suleimanov, Valery MIKUSINCOVA, Romana Zane, Silvia Kaaret, Philip MULERI, FABIO Poutanen, Juri MALACARIA, Christian Petrucci, Pierre-Olivier Gau, Ephraim Hu, Kun Chun, Sohee Agudo, Iván ANTONELLI, Lucio Angelo BACHETTI, Matteo Baldini, Luca Baumgartner, Wayne H. Bellazzini, Ronaldo Bongiorno, Stephen D. Bonino, Raffaella Brez, Alessandro BUCCIANTINI, Niccolo' Castellano, Simone Cavazzuti, Elisabetta Chen, Chien-Ting Ciprini, Stefano COSTA, ENRICO DE ROSA, Alessandra DEL MONTE, Ettore Di Gesu, Laura Di Lalla, Niccolò DI MARCO, Alessandro Donnarumma, Immacolata Doroshenko, Victor Ehlert, Steven R. Enoto, Teruaki EVANGELISTA, YURI FABIANI, Sergio FERRAZZOLI, Riccardo García, Javier A. Gunji, Shuichi Hayashida, Kiyoshi Heyl, Jeremy Iwakiri, Wataru Jorstad, Svetlana G. Kislat, Fabian Kitaguchi, Takao Kolodziejczak, Jeffery J. LA MONACA, Fabio Latronico, Luca Liodakis, Ioannis Maldera, Simone Manfreda, Alberto Marin, Frédéric Marinucci, Andrea Marscher, Alan P. Marshall, Herman L. MASSARO, Francesco Mitsuishi, Ikuyuki Mizuno, Tsunefumi Ng, Chi-Yung O'Dell, Stephen L. Omodei, Nicola Oppedisano, Chiara PAPITTO, ALESSANDRO Pavlov, George G. Peirson, Abel L. PERRI, Matteo Pesce-Rollins, Melissa PILIA, Maura POSSENTI, ANDREA Puccetti, Simonetta Ramsey, Brian D. RANKIN, John Roberts, Oliver J. Romani, Roger W. Sgrò, Carmelo Slane, Patrick Spandre, Gloria SOFFITTA, PAOLO Swartz, Douglas A. Tamagawa, Toru TAVECCHIO, Fabrizio Tawara, Yuzuru |
Issue Date: | 2023 |
Journal: | THE ASTROPHYSICAL JOURNAL LETTERS |
Number: | 958 |
Issue: | 1 |
First Page: | L8 |
Abstract: | The Imaging X-ray Polarimetry Explorer (IXPE) observed the black hole X-ray binary 4U 1630-47 in the steep power-law (or very high) state. The observations reveal a linear polarization degree of the 2-8 keV X-rays of 6.8% ± 0.2% at a position angle of 21.°3 ± 0.°9 east of north (all errors at 1σ confidence level). Whereas the polarization degree increases with energy, the polarization angle stays constant within the accuracy of our measurements. We compare the polarization of the source in the steep power-law state with the previous IXPE measurement of the source in the high soft state. We find that, even though the source flux and spectral shape are significantly different between the high soft state and the steep power-law state, their polarization signatures are similar. Assuming that the polarization of both the thermal and power-law emission components are constant over time, we estimate the power-law component polarization to be 6.8%-7.0% and note that the polarization angle of the thermal and power-law components must be approximately aligned. We discuss the implications for the origin of the power-law component and the properties of the emitting plasma. |
URI: | http://hdl.handle.net/20.500.12386/35712 |
URL: | https://api.elsevier.com/content/abstract/scopus_id/85177743587 https://iopscience.iop.org/article/10.3847/2041-8213/acfd2c |
ISSN: | 2041-8205 |
DOI: | 10.3847/2041-8213/acfd2c |
Bibcode ADS: | 2023ApJ...958L...8R |
Fulltext: | open |
Appears in Collections: | 1.01 Articoli in rivista
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