{"paper":{"title":"The Halo Black-Hole X-ray Transient XTE J1118+480","license":"","headline":"","cross_cats":[],"primary_cat":"astro-ph","authors_text":"C. B. Foltz, J. Casares, P. A. Charles, P. Hewett, R. M. Wagner, S. G. Starrfield, T. Shahbaz","submitted_at":"2001-04-02T22:56:33Z","abstract_excerpt":"Optical spectra were obtained of the optical counterpart of the high latitude soft X-ray transient XTE J1118+480 near its quiescent state with the new 6.5 m MMT and the 4.2 m WHT. The spectrum exhibits broad, double-peaked, emission lines of hydrogen from an accretion disk superposed with absorption lines of a K7V-M0V secondary star. Cross-correlation of the 27 individual spectra with late-type stellar template spectra reveals a sinusoidal variation in radial velocity with amplitude K = 701 +/- 10 km/s and orbital period P = 0.169930 +/- 0.000004 d. The mass function, 6.1 +/- 0.3 solar masses,"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"astro-ph/0104032","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"}