{"paper":{"title":"Recovery of the X-ray polarisation of Swift J1727.8$-$1613 after the soft-to-hard spectral transition","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"A. Ingram, A. Ratheesh, A. Veledina, E. Egron, E. Nathan, F. Capitanio, F. Muleri, F. Tombesi, G. Mastroserio, G. Matt, H. Krawczynski, J. A. Garc\\'ia, J. F. Steiner, J. Podgorn\\'y, J. Poutanen, J. Svoboda, K. Hu, L. Marra, M. Brigitte, M. Dov\\v{c}iak, M. Negro, M. N. Iacolina, N. Bollemeijer, N. Castro Segura, N. Rodriguez Cavero, P. Kaaret, P.-O. Petrucci, R. Emami, R. Taverna, S. Bianchi, S. R. Datta, T. D. Russell, T. Mu\\~noz-Darias, V. Kravtsov, W. Zhang, Y. J. Yang, Y. Zhang","submitted_at":"2024-04-30T14:51:41Z","abstract_excerpt":"We report on the detection of X-ray polarisation in the black-hole X-ray binary Swift J1727.8$-$1613 during its dim hard spectral state by the Imaging X-ray Polarimetry Explorer (IXPE). This is the first detection of X-ray polarisation at the transition from the soft to the hard state in an X-ray binary. We find an averaged 2$-$8 keV polarisation degree of (3.3 ${\\pm}$ 0.4) % and a corresponding polarisation angle of 3{\\deg} ${\\pm}$ 4{\\deg}, which matches the polarisation detected during the rising stage of the outburst, in September$-$October 2023, within 1${\\sigma}$ uncertainty. The observat"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2404.19601","kind":"arxiv","version":3},"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/2404.19601/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"}