COLD WATER VAPOR IN THE BARNARD 5 MOLECULAR CLOUD
Journal article, 2014
After 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 (similar to 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 = 1(10)-1(01)) 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.
stars: formation
EMISSION
ISM: individual objects (Barnard 5)
CH3OH
1983
WAVE-ASTRONOMY-SATELLITE
P603
STAR-FORMING REGIONS
Astronomy & Astrophysics
LINE OBSERVATIONS
submillimeter: ISM
ASAD SS
V267
CORES
ISM: molecules
astrochemistry
ROTATIONAL-EXCITATION
HERSCHEL
DENSE CLOUDS
ASTROPHYSICAL JOURNAL
RADIATIVE-TRANSFER
Author
Eva Wirström
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
S. B. Charnley
National Aeronautics and Space Administration (NASA)
Carina Persson
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
J. V. Buckle
University of Cambridge
Kavli Institute for Cosmology
M. A. Cordiner
Catholic University of America
National Aeronautics and Space Administration (NASA)
S. Takakuwa
Academia Sinica
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 788 2 L32Subject Categories (SSIF 2011)
Fusion, Plasma and Space Physics
DOI
10.1088/2041-8205/788/2/l32