Circumstellar envelope of W3(OH) - NH3 observations

Journal Article · Thu Jan 01 04:00:00 EST 1987 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/164929· OSTI ID:6399424

Reid, M J; Myers, P C; Bieging, J H

Observations of absorption in the 1.3 cm (J,K) = (1,1) amd (2,2) lines of NH3 toward the ultracompact H II region W3(OH) made at subarcsecond resolution with the VLA are reported. Maps of optical depth, beam-filling factor, column density, and rotational temperature are presented. The NH3 absorption is similar to the OH maser emission in velocity, extent, and location, a result which suggests that both species are constituents of the same clumpy molecular envelope. The optical depths are nearly constant across the maps, while the beam-filling factors and the (2,2)-(1,1) rotational temperature decrease from west to east. The NH3 maps and the OH maser results indicate that the thermal and turbulent pressures in the ultracompact H II region are comparable to the magnetic and ram pressures from the surrounding neutral material that appears to be falling inward. 27 references.

• Research Organization: Harvard-Smithsonian Center for Astrophysics, Cambridge, MA; California Univ., Berkeley
• OSTI ID: 6399424
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 312; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
AMMONIA
COSMIC GASES
COSMIC RADIO SOURCES
ELECTROMAGNETIC RADIATION
FLUIDS
GASES
H2 REGIONS
HYDRIDES
HYDROGEN COMPOUNDS
INTERSTELLAR MAGNETIC FIELDS
MAGNETIC FIELDS
NEBULAE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
RADIATIONS
RADIOWAVE RADIATION
SPECTRA
STAR EVOLUTION