{"paper":{"title":"Cosmic histories of star formation and reionization: An analysis with a power-law approximation","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["astro-ph.HE"],"primary_cat":"astro-ph.CO","authors_text":"K. S. Cheng, M. C. Chu, S. Yeung, Yun-Wei Yu","submitted_at":"2012-07-11T02:03:57Z","abstract_excerpt":"With a simple power-law approximation of high-redshift ($\\gtrsim3.5$) star formation history, i.e., $\\dot{\\rho}_*(z)\\propto [(1+z)/4.5]^{-\\alpha}$, we investigate the reionization of intergalactic medium (IGM) and the consequent Thomson scattering optical depth for cosmic microwave background (CMB) photons. A constraint on the evolution index $\\alpha$ is derived from the CMB optical depth measured by the {\\it Wilkinson Microwave Anisotropy Probe} (WMAP) experiment, which reads $\\alpha\\approx2.18\\lg{\\mathscr{N}_{\\gamma}}-3.89$, where the free parameter $\\mathscr{N}_\\gamma$ is the number of the "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.2526","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"}