{"paper":{"title":"First detection of X-ray polarization from the accreting neutron star 4U 1820-303","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Abel L. Peirson, Ajay Ratheesh, Alan P. Marscher, Alberto Manfreda, Alessandra De Rosa, Alessandro Brez, Alessandro Di Marco, Alessandro Papitto, Alessio Anitra, Alessio Marino, Alessio Trois, Allyn F. Tennant, Andrea Gnarini, Andrea Marinucci, Andrea Possenti, Andrea Sanna, Anna Bobrikova, Antonella Tarana, Brian D. Ramsey, Carmelo Sgr\\`o, Chiara Oppedisano, Chien-Ting Chen, Chi-Yung Ng, Douglas A. Swartz, Elisabetta Cavazzuti, Enrico Costa, Ettore Del Monte, Fabian Kislat, Fabio La Monaca, Fabio Muleri, Fabrizio Tavecchio, Fei Xie, Fiamma Capitanio, Filippo Ambrosino, Francesco Carotenuto, Francesco Massaro, Francesco Tombesi, Francesco Ursini, Frederic Marin, George G. Pavlov, Giorgio Matt, Gloria Spandre, Guglielmo Mastroserio, Henric Krawczynski, Herman L. Marshall, Ikuyuki Mitsuishi, Immacolata Donnarumma, Ioannis Liodakis, Ivan Agudo, Jacco Vink, Jakob van den Eijnden, Jari J. E. Kajava, Javier A. Garcia, Jeffery J. Kolodziejczak, Jeremy Heyl, John Rankin, Juri Poutanen, Kinwah Wu, Kiyoshi Hayashida, Kuan Liu, Laura Di Gesu, Luca Baldini, Luca Latronico, Luciano Burderi, Lucio A. Antonelli, Luigi Stella, Martin C. Weisskopf, Massimo Cocchi, Matteo Bachetti, Matteo Perri, Maura Pilia, Melania Del Santo, Melissa Pesce-Rollins, Michal Dovciak, Michela Negro, Niccolo Bucciantini, Niccolo Di Lalla, Nicholas E. Thomas, Nicola Omodei, Oliver J. Roberts, Paolo Soffitta, Patrick Slane, Philip Kaaret, Pierre-Olivier Petrucci, Raffaella Bonino, Riccardo Ferrazzoli, Riccardo Middei, Roberto Taverna, Roberto Turolla, Roger W. Romani, Ronaldo Bellazzini, Rosario Iaria, Ruben Farinelli, Sara Elisa Motta, Sergey S. Tsygankov, Sergio Fabiani, Shuichi Gunji, Silvia Zane, Simone Castellano, Simone Maldera, Simonetta Puccetti, Stefano Bianchi, Stefano Ciprini, Stephen D. Bongiorno, Stephen L. O'Dell, Steven R. Ehlert, Svetlana G. Jorstad, Takao Kitaguchi, Teruaki Enoto, Thomas D. Russell, Tiziana Di Salvo, Toru Tamagawa, Tsunefumi Mizuno, Victor Doroshenko, Vladimir Karas, Wataru Iwakiri, Wayne H. Baumgartner, Yuri Evangelista, Yuzuru Tawara","submitted_at":"2023-06-14T12:45:58Z","abstract_excerpt":"This paper reports the first detection of polarization in the X-rays for atoll-source 4U 1820-303, obtained with the Imaging X-ray Polarimetry Explorer (IXPE) at 99.999% confidence level (CL). Simultaneous polarimetric measurements were also performed in the radio with the Australia Telescope Compact Array (ATCA). The IXPE observations of 4U 1820-303 were coordinated with Swift-XRT, NICER, and NuSTAR aiming to obtain an accurate X-ray spectral model covering a broad energy interval. The source shows a significant polarization above 4 keV, with a polarization degree of 2.0(0.5)% and a polarizat"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2306.08476","kind":"arxiv","version":4},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2306.08476/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}