Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Rotating and expanding ultracompact H II regions

Journal Article · · Astrophys. J.; (United States)
DOI:https://doi.org/10.1086/164624· OSTI ID:6836550
The H76-alpha recombination line and radio continuum emission was observed from two compact H II regions, G34.3+0.2 and G45.07+0.13. The line center velocity of G34.3+0.2 shows a remarkably gradual shift across the source by about 23 km/s. The corresponding velocity gradient of about 3 x 10 to the -11th/s is the largest observed to date among either young regions of star formation or dark interstellar clouds. The radio continuum appearance of G34.3+0.2 may result from the H II region being embedded in a dense molecular slab and experiencing the champagne phase of its evolution. The velocity and radio continuum structure of G45.07+0.13 suggest the existence of an ionized ring that is expanding at a velocity of 10 km/s with respect to the central star. 43 references.
Research Organization:
European Southern Observatory, Garching, West Germany; Universidad Nacional Autonoma de Mexico, Alvaro Obregon, Mexico; National Radio Astronomy Observatory, Socorro, NM
OSTI ID:
6836550
Journal Information:
Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 309; ISSN ASJOA
Country of Publication:
United States
Language:
English

Similar Records

Cometary compact H II regions are stellar-wind bow shocks
Journal Article · Sat Mar 31 23:00:00 EST 1990 · Astrophysical Journal; (USA) · OSTI ID:6769993

A VERY LARGE ARRAY STUDY OF ULTRACOMPACT AND HYPERCOMPACT H II REGIONS FROM 0.7 TO 3.6 cm
Journal Article · Wed Jun 01 00:00:00 EDT 2011 · Astrophysical Journal, Supplement Series · OSTI ID:21560360

The dynamics and physical properties of the cometary nebula G29. 96 - 0. 02
Journal Article · Wed May 01 00:00:00 EDT 1991 · Astrophysical Journal; (United States) · OSTI ID:5587689