NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Bow shock models for the velocity structure of ultracompact H II regionsThe velocity structure of ultracompact H II regions is modeled assuming that O stars moving supersonically through molecular clouds sweep up bow shocks to produce the observed objects. The expected radio recombination line emission is calculated for the case of an optically thin continuum and the strong effect of changing the viewing angle is shown. The kinematic information removes the degeneracy with ram pressure of a previous model, allowing measurement of stellar velocity vectors and cloud densities. A detailed model for G29.96-0.02 shows good agreement with observations by Wood and Churchwell, supporting the bow shock hypothesis. It is found that the exciting star of G29 is moving at 20 km/s relative to the gas, suggesting that O stars acquire a large velocity dispersion early in their lives.
Document ID
19920066791
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Van Buren, Dave
(California Institute of Technology; JPL Pasadena, United States)
Mac Low, Mordecai-Mark
(California, University, Berkeley; NASA, Ames Research Center Moffett Field, United States)
Date Acquired
August 15, 2013
Publication Date
August 1, 1992
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 394
Issue: 2, Au
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
92A49415
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available