COLD WATER VAPOR IN THE BARNARD 5 MOLECULAR CLOUD
Artikel i vetenskaplig tidskrift, 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

Författare

Eva Wirström

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

S. B. Charnley

NASA Goddard Space Flight Center

Carina Persson

Chalmers, Rymd- och geovetenskap, Radioastronomi och astrofysik

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 L32

Ämneskategorier

Fusion, plasma och rymdfysik

DOI

10.1088/2041-8205/788/2/l32