HERSCHEL OBSERVATIONS of INTERSTELLAR CHLORONIUM. II. DETECTIONS TOWARD G29.96-0.02, W49N, W51, and W3(OH), and DETERMINATIONS of the ORTHO-TO-PARA and 35Cl/37Cl ISOTOPIC RATIOS
Artikel i vetenskaplig tidskrift, 2015

We report additional detections of the chloronium molecular ion, H2Cl+, toward four bright submillimeter continuum sources: G29.96-0.02, W49N, W51, and W3(OH). With the use of the HIFI instrument on board the Herschel Space Observatory, we observed the 212-101 transition of ortho-H235Cl+ at 781.627 GHz in absorption toward all four sources. Much of the detected absorption arises in diffuse foreground clouds that are unassociated with the background continuum sources and in which our best estimates of the N(H2Cl+)/N(H) ratio lie in the range (0.9-4.8)× 10-9. These chloronium abundances relative to atomic hydrogen can exceed the predictions of current astrochemical models by up to a factor of 5. Toward W49N, we have also detected the 212-101 transition of ortho-H237Cl+ at 780.053 GHz and the 111-000 transition of para-H235Cl+ at 485.418 GHz. These observations imply H235Cl+/H237Cl+ column density ratios that are consistent with the solar system 35Cl/37Cl isotopic ratio of 3.1, and chloronium ortho-to-para ratios consistent with 3, the ratio of spin statistical weights.

Författare

D.A. Neufeld

Johns Hopkins University

John H Black

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

M. Gerin

Université Pierre et Marie Curie (UPMC)

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

J.R. Goicoechea

CSIC - Instituto de Ciencia de Materiales de Madrid (ICMM)

P.F. Goldsmith

Jet Propulsion Laboratory, California Institute of Technology

C. Gry

Laboratoire d'Astrophysique de Marseille

H. Gupta

CalTech

E. Herbst

University of Virginia

N. Indriolo

University of Michigan

D. Lis

LERMA - Laboratoire d'Etudes du Rayonnement et de la Matiere en Astrophysique et Atmospheres

CalTech

K.M. Menten

Max Planck-institutet

Raquel Rodriguez-Monje

CalTech

B. Mookerjea

Tata Institute of Fundamental Research

Carina Persson

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

P. Schilke

Universität zu Köln

P. Sonnentrucker

Space Telescope Science Institute (STScI)

M.G. Wolfire

University of Maryland

Astrophysical Journal

0004-637X (ISSN) 1538-4357 (eISSN)

Vol. 807 1 54

Ämneskategorier

Fusion, plasma och rymdfysik

DOI

10.1088/0004-637X/807/1/54