The distribution and kinematics of ammonia in the Orion-KL nebula - high-sensitivity VLA maps of the NH sub 3 (3,2) line

Journal Article · Fri Dec 01 04:00:00 EST 1989 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/168118· OSTI ID:7058359

Migenes, V; Johnston, K J; Pauls, T A; Wilson, T L ^[1]

---

1. Pennsylvania Univ., Philadelphia (USA) E. O. Hulburt Center for Space Research, Washington, DC (USA) Max-Planck-Institut fuer Radioastronomie, Bonn (Germany, F.R.)

VLA maps of the (J,K) = (3,2) rotation-inversion line of NH{sub 3} toward the Orion-KL nebula are presented which show that the emission is clumped on roughly 1 arcsec scales. There are 11 distinct fragments with peak intensities more than seven times the rms noise. The observations give a qualitatively different picture of the fragmentation process on scales of 10 to the 16th cm. Apparently, turbulent motions within the individual clumps are small, and most of the kinetic energy is contained in orbital motion. For VLA observations, it is found that the (3,2) line spectra agree better with spectra of other nonmetastable (J greater than K) lines than with metastable (J = K) lines. This confirms that the nonmetastable and metastable NH3 lines are formed in different regions of the hot core. The maps show that the structure in the hot core is consistent with a clumpy cylinder whose axis is inclined at about 40 deg east of north and expanding at 10 km/s. 24 refs.

• OSTI ID: 7058359
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 347; ISSN ASJOA; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMMONIA
EMISSION SPECTRA
HYDRIDES
HYDROGEN COMPOUNDS
INTERSTELLAR SPACE
LINE WIDTHS
MAPS
MASS
MOTION
NEBULAE
NITROGEN COMPOUNDS
NITROGEN HYDRIDES
PARTICLE KINEMATICS
ROTATION
SPACE
SPECTRA
SPECTROSCOPY
STAR EVOLUTION
TURBULENCE