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Cold Water Vapor in the Barnard 5 Molecular CloudAfter more than 30 yr of investigations, the nature of gas-grain interactions at low temperatures remains an unresolved issue in astrochemistry. Water ice is the dominant ice found in cold molecular clouds; however, there is only one region where cold ((is) approximately 10 K) water vapor has been detected-L1544. This study aims to shed light on ice desorption mechanisms under cold cloud conditions by expanding the sample. The clumpy distribution of methanol in dark clouds testifies to transient desorption processes at work-likely to also disrupt water ice mantles. Therefore, the Herschel HIFI instrument was used to search for cold water in a small sample of prominent methanol emission peaks. We report detections of the ground-state transition of o-H2O (J = 110-101) at 556.9360 GHz toward two positions in the cold molecular cloud, Barnard 5. The relative abundances of methanol and water gas support a desorption mechanism which disrupts the outer ice mantle layers, rather than causing complete mantle removal.


Document ID
20150008363
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Wirstrom, E. S.
(Chalmers Univ. of Technology Goeteborg, Sweden)
Charnley, S. B.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Persson, C. M.
(Chalmers Univ. of Technology Goeteborg, Sweden)
Buckle, J. V.
(Cambridge Univ. Cambridge, United Kingdom)
Cordiner, M. A.
(Catholic Univ. of America Washington, DC, United States)
Takakuwa, S.
(Academia Sinica Taipei, Taiwan, Province of China)
Date Acquired
May 19, 2015
Publication Date
June 4, 2014
Publication Information
Publication: The Astrophysical Journal Letters
Publisher: iop science
Volume: 788
Issue: 2
Subject Category
Space Sciences (General)
Report/Patent Number
GSFC-E-DAA-TN21495
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
ISM: molecules
stars: formation aEuro" submillimeter: ISM
ISM: individual objects
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