{"paper":{"title":"The discovery of the 401 Hz accreting millisecond pulsar IGR J17498-2921 in a 3.8 hr orbit","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"(2) ISDC, (3) INAF OA-Brera, (4) Univ. Palermo, (5) INAF OA-Cagliari), A.D'A\\`i (4), A. Papitto (1), A. Riggio (5), C. Ferrigno (2), E. Bozzo (2), L. Burderi (1), R. Iaria (4) ((1) Univ. Cagliari, T. Di Salvo (4), T. M. Belloni (3)","submitted_at":"2011-11-08T17:10:12Z","abstract_excerpt":"We report on the detection of a 400.99018734(1) Hz coherent signal in the Rossi X-ray Timing Explorer light curves of the recently discovered X-ray transient, IGR J17498-2921. By analysing the frequency modulation caused by the orbital motion observed between August 13 and September 8, 2011, we derive an orbital solution for the binary system with a period of 3.8432275(3) hr. The measured mass function, f(M_2, M_1, i)=0.00203807(8) Msun, allows to set a lower limit of 0.17 Msun on the mass of the companion star, while an upper limit of 0.48 Msun is set by imposing that the companion star does "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1111.1976","kind":"arxiv","version":1},"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"}