{"paper":{"title":"X-ray Variability and Hardness of ESO 243-49 HLX-1: Clear Evidence for Spectral State Transitions","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.HE","authors_text":"Dacheng Lin, Didier Barret, Mathieu Servillat, Natalie A. Webb, Olivier Godet, Sean A. Farrell","submitted_at":"2011-08-22T19:49:02Z","abstract_excerpt":"The ultra-luminous X-ray (ULX) source ESO 243-49 HLX-1 currently provides the strongest evidence for the existence of intermediate mass black holes. We conduct an ongoing monitoring campaign with the Swift X-ray Telescope and found that HLX-1 showed two fast rise and exponential decay with increases in the count rate of a factor ~40 separated by 375+/-13 days. We obtained new XMM-Newton and Chandra dedicated pointings that were triggered at the lowest and highest luminosities, respectively. The unabsorbed luminosities ranged from 1.9x10^40 to 1.25x10^42 erg/s. We confirm here the detection of "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1108.4405","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"}