{"paper":{"title":"Low-Resolution Spectroscopy of Gamma-ray Burst Optical Afterglows: Biases in the Swift Sample and Characterization of the Absorbers","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.CO","authors_text":"A. Castro-Tirado, A. De Cia, A. de Ugarte Postigo, A. Jaunsen, A. Levan, A. S. Fruchter, B. L. Jensen, B. Milvang-Jensen, C. C. Thoene, C. Kouveliotou, C. Ledoux, D. A. Kann, D. A. Perley, D. J. Watson, D. Malesani, D. Xu, E. Palazzi, E. Pian, E. Rol, F. Grundahl, G. Bjoernsson, H.-W. Chen, J. F. Graham, J. Hjorth, J. Maund, J. P. U. Fynbo, J. S. Bloom, J. Sollerman, J. Telting, J. U. Gorosabel, J. X. Prochaska, K. Wiersema, L. Christensen, M. Nardini, N. Masetti, N. Tanvir, P. Jakobsson, P. M. Vreeswijk, P.-O. Quirion, P. Schady, R. Starling, T. Augusteijn","submitted_at":"2009-07-20T19:13:26Z","abstract_excerpt":"(Abridged). We present a sample of 77 optical afterglows (OAs) of Swift detected GRBs for which spectroscopic follow-up observations have been secured. We provide linelists and equivalent widths for all detected lines redward of Ly-alpha. We discuss to what extent the current sample of Swift bursts with OA spectroscopy is a biased subsample of all Swift detected GRBs. For that purpose we define an X-ray selected sample of Swift bursts with optimal conditions for ground-based follow up from the period March 2005 to September 2008; 146 bursts fulfill our sample criteria. We derive the redshift d"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0907.3449","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/0907.3449/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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"}