{"paper":{"title":"A Hard X-Ray Power-Law Spectral Cutoff in Centaurus X-4","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Brian W. Grefenstette (Caltech), Charles J. Hailey (Columbia), Daniel R. Wik (NASA/GSFC), Daniel Stern (JPL/Caltech), Deepto Chakrabarty (MIT), Didier Barret (IRAP/Toulouse), Dimitrios Psaltis (Arizona), Felix Fuerst (Caltech), Finn E. Christensen (DTU space), Fiona A. Harrison (Caltech), Joern Wilms (Erlangen-Nuremberg), John A. Tomsick (Berkeley), Jon M. Miller (Michigan), Matteo Bachetti (IRAP/Toulouse), Michael A. Nowak (MIT), Steven E. Boggs (Berkeley), Victoria A. Kaspi (McGill), Vikram Rana (Caltech), William W. Craig (LLNL/Berkeley), William W. Zhang (NASA/GSFC)","submitted_at":"2014-03-26T17:06:26Z","abstract_excerpt":"The low-mass X-ray binary Cen X-4 is the brightest and closest (<1.2 kpc) quiescent neutron star transient. Previous 0.5-10 keV X-ray observations of Cen X-4 in quiescence identified two spectral components: soft thermal emission from the neutron star atmosphere and a hard power-law tail of unknown origin. We report here on a simultaneous observation of Cen X-4 with NuSTAR (3-79 keV) and XMM-Newton (0.3-10 keV) in 2013 January, providing the first sensitive hard X-ray spectrum of a quiescent neutron star transient. The 0.3-79 keV luminosity was 1.1 x 10^(33) erg/s (for D=1kpc), with around 60 "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1403.6751","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"}