VLA Observations of Class I Methanol Masers in the Region of Low-Mass Star Formation L1157
Artikel i vetenskaplig tidskrift, 2010
We present the results of VLA observations of a maser candidate in the low-mass star formation region L1157 in the 7(0)-6(1) A(+) transition at 44 GHz. The line is emitted by a compact, undoubtedly maser source associated with clump B0a, which is seen in maps of L1157 in thermal lines of methanol and other molecules. A much weaker compact source is associated with clump B1a, which is brighter than B0a in thermal methanol lines. The newly detected masers may form in thin layers of turbulent post-shock gas. In this case, the maser emission may be beamed, so that only an observer located in or near the planes of the layers can observe strong masers. On the other hand, the maser lines are double with a "red" asymmetry, indicating that the masers may form in collapsing clumps. A detailed analysis of collapsing-cloud maser models and their applicability to the masers in L1157 will be developed in subsequent papers.
ghz
line
1157 molecular outflow
Författare
S. V. Kalenskii
Russian Academy of Sciences
S. Kurtz
Universidad Nacional Autónoma de México
V. I. Slysh
Russian Academy of Sciences
P. Hofner
National Radio Astronomy Observatory Socorro
Max-Planck-Gesellschaft
New Mexico Institute of Mining and Technology
C. M. Walmsley
Osservatorio Astrofisico di Arcetri
Lars E B Johansson
Chalmers, Institutionen för radio- och rymdvetenskap, Nationella anläggningen för radioastronomi
Per Bergman
Chalmers, Institutionen för radio- och rymdvetenskap, Nationella anläggningen för radioastronomi
Astronomy Reports
1063-7729 (ISSN) 1562-6881 (eISSN)
Vol. 54 10 932-939Ämneskategorier
Astronomi, astrofysik och kosmologi
DOI
10.1134/S1063772910100069