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.
astrochemistry
1983
ROTATIONAL-EXCITATION
LINE OBSERVATIONS
P603
submillimeter: ISM
ASTROPHYSICAL JOURNAL
ISM: individual objects (Barnard 5)
Astronomy & Astrophysics
V267
HERSCHEL
ASAD SS
ISM: molecules
WAVE-ASTRONOMY-SATELLITE
CORES
stars: formation
CH3OH
EMISSION
STAR-FORMING REGIONS
RADIATIVE-TRANSFER
DENSE CLOUDS
Author
Eva Wirström
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
S. B. Charnley
NASA Goddard Space Flight Center
Carina Persson
Chalmers, Earth and Space Sciences, Radio Astronomy and Astrophysics
J. V. Buckle
Kavli Institute for Cosmology
University of Cambridge
M. A. Cordiner
Catholic University of America
NASA Goddard Space Flight Center
S. Takakuwa
Institute of Astrophysics and Astronomy, Academia Sinica Taiwan
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