VLA observations of warm NH/sub 3/ associated with mass outflows in W51

Journal Article · Tue Mar 15 04:00:00 EST 1983 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160807· OSTI ID:5894965

Ho, P T.P.

We present VLA observations of the (J,K) = (3,3) inversion line of NH/sub 3/ toward the distant H II region complex in W51. Three small (approx.0.1 pc), warm (approx.100 K) NH/sub 3/ condensations are found coincident with every one of the H/sub 2/O and OH maser sources in the region. This positional coincidence, as well as the observed large line widths (> or =10 km s/sup -1/), suggests that the localized NH/sub 3/ emission arises from dense molecular condensations which are interacting with the mass outflows from young stars in these regions. These observations also represent the first direct detection of such high gas temperature outside the Orion-KL region. Gas heating could be due to the radiation from the exciting sources of the compact H II regions and masers or from the input of mechanical energy due to the outflows. These warm condensations are embedded in a cooler and more extended envelope which dominates lower angular resolution studies.

• Research Organization: Radio Astronomy Laboratory, University of California, Berkeley
• OSTI ID: 5894965
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 266:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMMONIA
AMPLIFIERS
COSMIC RADIO SOURCES
ELECTRONIC EQUIPMENT
EQUIPMENT
H2 REGIONS
HYDRIDES
HYDROGEN COMPOUNDS
INTERFEROMETRY
INTERSTELLAR GRAINS
MAPS
MASERS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
PARTICLES
SPECTRA