{"paper":{"title":"Very blue UV-continuum slopes of low luminosity z~7 galaxies from WFC3/IR: Evidence for extremely low metallicities?","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"D. Magee (UCSC), G.D. Illingworth (UCSC), I. Labbe (OCIW), M. Carollo (ETH Zurich), M. Franx (Leiden), M. Stiavelli (STScI), M. Trenti (Colorado), P.A. Oesch (ETH Zurich), P.G. van Dokkum (Yale), R.J. Bouwens (UCSC/Leiden)","submitted_at":"2009-10-01T19:42:13Z","abstract_excerpt":"We use the ultra-deep WFC3/IR data over the HUDF and the Early Release Science WFC3/IR data over the CDF-South GOODS field to quantify the broadband spectral properties of candidate star-forming galaxies at z~7. We determine the UV-continuum slope beta in these galaxies, and compare the slopes with galaxies at later times to measure the evolution in beta. For luminous L*(z=3) galaxies, we measure a mean UV-continuum slope beta of -2.0+/-0.2, which is comparable to the beta~-2 derived at similar luminosities at z~5-6. However, for the lower luminosity 0.1L*(z=3) galaxies, we measure a mean beta"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0910.0001","kind":"arxiv","version":4},"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"}