Year: 2026
Type: article
Abstract: RCW 86 is a supernova remnant whose origin has recently been linked to an off-center explosion within a cavity created by its progenitor star. In the southwestern region, the forward shock is thought to have reached the cavity wall, encountering diverse environmental conditions. We report on the spatially resolved X-ray polarimetric observation of RCW 86 with the Imaging X-ray Polarimetry Explorer (IXPE). In the 2–4.5 keV energy band we find no significant detection of polarization. Employing a dedicated background subtraction procedure and Bayesian spectropolarimetric fitting, we derive 99% upper limits on the polarization degree of the synchrotron component: 15% in higher-statistics regions and 30%–40% in lower-statistics regions. These upper limits on the polarization degree in several regions exclude the possibility of a strongly coherent magnetic field down to the subparsec scale, and that of a moderately coherent one on the scale of the synchrotron features as resolved by IXPE. The results indicate that the shocks in the southwestern rim of RCW 86 propagate more slowly than the unshocked ejecta at their locations, yet exceed the measured proper motion speeds. This behavior is consistent with reflected shocks occurring in tenuous regions of the shocked ejecta, distinct from regions that are radio-bright.
Source: The Astrophysical Journal
Authors: Stefano Silvestri, Dmitry Prokhorov, Jacco Vink, Patrick Slane, Yi-Jung Yang, Niccolò Bucciantini, Riccardo Ferrazzoli, Ping Zhou, Enrico Costa, Nicola Omodei, Chi-Yung Ng, Paolo Soffitta, Martin C. Weisskopf, Luca Baldini, Alessandro Di Marco, Victor Doroshenko, Jeremy Heyl, Philip Kaaret, Frédéric Marin, Tsunefumi Mizuno, Melissa Pesce-Rollins, Carmelo Sgrò, Douglas A. Swartz, Toru Tamagawa, Fei Xie, Iván Agudo, Lucio A. Antonelli, Matteo Bachetti, Wayne H. Baumgartner, Ronaldo Bellazzini, Stefano Bianchi, Stephen D. Bongiorno, Raffaella Bonino, Alessandro Brez, Fiamma Capitanio, Simone Castellano, Elisabetta Cavazzuti, Chien-Ting Chen, Stefano Ciprini, Alessandra De Rosa, Ettore Del Monte, Laura Di Gesu, Niccolò Di Lalla, Immacolata Donnarumma, Michal Dovčiak, Steven R. Ehlert, Teruaki Enoto, Yuri Evangelista, Sergio Fabiani, Javier A. García, Shuichi Gunji, Kiyoshi Hayashida, Wataru Iwakiri, Svetlana G. Jorstad, Vladimir Karas, Fabian Kislat, Takao Kitaguchi, Jeffery J. Kolodziejczak, Henric Krawczynski, Fabio La Monaca, Luca Latronico, Ioannis Liodakis, Simone Maldera, Alberto Manfreda, Andrea Marinucci, Alan P. Marscher, Herman L. Marshall, Francesco Massaro, Giorgio Matt, Ikuyuki Mitsuishi, Fabio Muleri, Michela Negro, Stephen L. O’Dell, Chiara Oppedisano, Alessandro Papitto, George G. Pavlov, Abel L. Peirson, Matteo Perri, Pierre-Olivier Petrucci, Maura Pilia, Andrea Possenti, Juri Poutanen, Simonetta Puccetti, Brian D. Ramsey, John Rankin, Ajay Ratheesh, Oliver J. Roberts, Roger W. Romani, Gloria Spandre, Fabrizio Tavecchio, Roberto Taverna, Yuzuru Tawara, Allyn F. Tennant, Nicholas E. Thomas, Francesco Tombesi, Alessio Trois, Sergey S. Tsygankov, Roberto Turolla, Kinwah Wu, Silvia Zane
Institutions: Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, University of Würzburg, University of Amsterdam, Center for Astrophysics Harvard & Smithsonian, New York University Abu Dhabi, Cyberport, University of Hong Kong, Arcetri Astrophysical Observatory, Istituto Nazionale di Fisica Nucleare, Sezione di Firenze, University of Florence, Institute for Space Astrophysics and Planetology, National Institute for Astrophysics, Nanjing University, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Marshall Space Flight Center, University of Pisa, University of Tübingen, University of British Columbia, Centre National de la Recherche Scientifique, Observatoire astronomique de Strasbourg, Université de Strasbourg, Hiroshima University, Universities Space Research Association, RIKEN, Guangxi University, Instituto de Astrofísica de Andalucía, Astronomical Observatory of Rome, Agenzia Spaziale Italiana, Osservatorio Astronomico di Cagliari, United States Naval Research Laboratory, Roma Tre University, Istituto Nazionale di Fisica Nucleare, Sezione di Torino, University of Turin, Istituto Nazionale di Fisica Nucleare, Istituto Nazionale di Fisica Nucleare, Roma Tor Vergata, Czech Academy of Sciences, Astronomical Institute, Goddard Space Flight Center, Yamagata University, The University of Osaka, Chiba University, Boston University, St Petersburg University, University of New Hampshire, Washington University in St. Louis, University of Rome Tor Vergata, Sapienza University of Rome, Foundation for Research and Technology Hellas, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Massachusetts Institute of Technology, Nagoya University, Louisiana State University, Pennsylvania State University, Institut de Planétologie et d'Astrophysique de Grenoble, Université Grenoble Alpes, University of Turku, Brera Astronomical Observatory, Physical Research Laboratory, University of Padua, University College London
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Aeronautics and Space Administration, European Commission, National Natural Science Foundation of China, Agenzia Spaziale Italiana, Istituto Nazionale di Astrofisica, Ministero degli Affari Esteri e della Cooperazione Internazionale, Istituto Nazionale di Fisica Nucleare, Hong Kong Government, Marshall Space Flight Center, Goddard Space Flight Center, HORIZON EUROPE European Research Council
Awards: G1044000631, G1556275917, G1592191403, G2232826951, G2362727648, G236304463, G273979858, G3528041363, G3993203323, G4096230270, G4103929414, G4641417469, G5968124160, G6008122062, G7322757637, G754392931, G7642730041, G796551035, Black hOle Optical-polarization TimE-domain Survey, G8626528583, G8652242523
OpenAlex ID: W7128438187