{"paper":{"title":"Herschel/HIFI observations of interstellar OH+ and H2O+ towards W49N: a probe of diffuse clouds with a small molecular fraction","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"astro-ph.GA","authors_text":"A. Coutens, A. Cros, A. G. G. M. Tielens, A. Lorenzani, B. Godard, B. Mookerjea, C. Gry, C. Joblin, C. Persson, C. Vastel, D. A. Neufeld, D. C. Lis, D. Teyssier, E. Dartois, E. Falgarone, E. Herbst, F. Boulanger, H. Gupta, J. Cernicharo, J. H. Black, J. Kre{\\l}owski, J. Mart{\\i}n-Pintado, J. Pearson, J. R. Goicoechea, J. Stutzki, J. Zmuidzinas, K. Klein, K. M. Menten, L. A. Samoska, M. De Luca, M. Gerin, M. Kazmierczak, M. Perault, M. Salez, M. Schmidt, P. Encrenaz, P. F. Goldsmith, P. Hennebelle, P. Hily-Blant, P. Rimmer, P. Sonnentrucker, R. Ko{\\l}os, R. Monje, R. Plume, R. Shipman, R. Szczerba, S. Philipp, S. Schlemmer, S. Yu, T. A. Bell, T. Giesen, T. G. Phillips, T. R. Geballe","submitted_at":"2010-07-06T20:00:00Z","abstract_excerpt":"We report the detection of absorption by interstellar hydroxyl cations and water cations, along the sight-line to the bright continuum source W49N. We have used Herschel's HIFI instrument, in dual beam switch mode, to observe the 972 GHz N = 1 - 0 transition of OH+ and the 1115 GHz 1(11) - 0(00) transition of ortho-H2O+. The resultant spectra show absorption by ortho-H2O+, and strong absorption by OH+, in foreground material at velocities in the range 0 to 70 km/s with respect to the local standard of rest. The inferred OH+/H2O+ abundance ratio ranges from ~ 3 to ~ 15, implying that the observ"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1007.0987","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"}