{"paper":{"title":"Herschel Search for O2 Toward the Orion Bar","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"{\\AA}ke Hjalmarson, Dariusz C. Lis, David A. Neufeld, David J. Hollenbach, Di Li, Edith Falgarone, Ewine F. van Dishoeck, Floris van der Tak, Gary J. Melnick, John H. Black, Laurent Pagani, Maryvonne Gerin, Michael J. Kaufman, Paul F. Goldsmith, Pierre Encrenaz, Ren\\'e Liseau, Ronald L. Snell, Volker Tolls","submitted_at":"2012-04-25T16:55:47Z","abstract_excerpt":"We report the results of a search for molecular oxygen (O2) toward the Orion Bar, a prominent photodissociation region at the southern edge of the HII region created by the luminous Trapezium stars. We observed the spectral region around the frequency of the O2 N_J = 3_3 - 1_2 transition at 487 GHz and the 5_4 - 3_4 transition at 774 GHz using the Heterodyne Instrument for the Far Infrared on the Herschel Space Observatory. Neither line was detected, but the 3sigma upper limits established here translate to a total line-of-sight O2 column density < 1.5 10^16 cm^-2 for an emitting region whose "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1204.5706","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"}