{"paper":{"title":"Discovery of 3 s pulsations from the Brightest Hard X-ray Source in M31","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"(2) Anton Pannekoek Institute for Astronomy, (3) Scuola Universitaria Superiore IUSS, 4, (4) INAF--Istituto di Astrofisica Spaziale e Fisica Cosmica - Milano, 5), (5) INFN--Istituto Nazionale di Fisica Nucleare, Alessandro Papitto (1), Andrea De Luca (4) ((1) INAF--Osservatorio Astronomico di Roma, Andrea Tiengo (3, Gian Luca Israel (1), Guillermo A. Rodr\\'iguez Castillo (1), Luigi Stella (1), Paolo Esposito (2), Sezione di Pavia), University of Amsterdam","submitted_at":"2018-04-29T01:22:09Z","abstract_excerpt":"We report the discovery with XMM-Newton of 3-s X-ray pulsations from 3XMM J004232.1+411314, a dipping source that dominates the hard X-ray emission of M31. This finding unambiguously assesses the neutron star (NS) nature of the compact object. We also measured an orbital modulation of 4.15 h and a projected semi-axis at $a_{\\mathrm{X}} \\sin i= 0.6$ lt-s, which implies a low-mass companion of about 0.2$-$0.3$M_{\\odot}$ assuming a NS of 1.5 $M_{\\odot}$ and an orbital inclination $i=70^{\\circ}-80^{\\circ}$. The barycentric orbit-corrected pulse period decreased by $\\sim$28 ms in about 16 yr, corre"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1804.10858","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"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"}