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.
DENSE CLOUDS
WAVE-ASTRONOMY-SATELLITE
stars: formation
ISM: molecules
RADIATIVE-TRANSFER
P603
astrochemistry
HERSCHEL
ISM: individual objects (Barnard 5)
ASAD SS
Astronomy & Astrophysics
V267
CORES
CH3OH
ASTROPHYSICAL JOURNAL
ROTATIONAL-EXCITATION
EMISSION
submillimeter: ISM
LINE OBSERVATIONS
1983
STAR-FORMING REGIONS
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
University of Cambridge
Kavli Institute for Cosmology
M. A. Cordiner
Catholic University of America
NASA Goddard Space Flight Center
S. Takakuwa
Academia Sinica
Astrophysical Journal Letters
2041-8205 (ISSN) 2041-8213 (eISSN)
Vol. 788 2 L32Subject Categories
Fusion, Plasma and Space Physics
DOI
10.1088/2041-8205/788/2/l32