Astronomy and Astrophysics – Astrophysics
Scientific paper
Jun 1986
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1986apj...305..467t&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 305, June 1, 1986, p. 467-483.
Astronomy and Astrophysics
Astrophysics
40
Astronomical Models, Interstellar Masers, Molecular Clouds, Molecular Collisions, Water Masers, Collisional Plasmas, Interstellar Matter, Plasma Density, Spectral Line Width, Stellar Winds
Scientific paper
High-velocity collisions between small, dense, neutral clouds or between a dense cloud and a dense shell can provide the energy source required to excite H2O maser emission. The radiative precursor from the surface of the collisional shock front rapidly diffuses through the cloud, heating the dust grains but leaving the H2 molecules cool. Transient maser emission occurs as the conditions for the Goldreich and Kwan (1974) 'hot-dust cold-gas' maser pump scheme are realized locally within the cloud. In time, the local maser action quenches due to the heating of the H2 molecules by collisions against the grains. Although this model cannot explain the very long-lived steady maser features, it is quite successful in explaining a number of the observed properties of the high-velocity features in such sources as Orion, W51, and W49. In particular, it provides a natural explanation for the rapid time variations, the narrow line widths, juxtaposition of high- and low-velocity features, and the short lifetimes which are frequently observed for the so-called high-velocity maser 'bullets' thought to be accelerated by strong stellar winds.
Tarter T. C.
Welch William J.
No associations
LandOfFree
A cloud collision model for water maser excitation does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A cloud collision model for water maser excitation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A cloud collision model for water maser excitation will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1830221