Thermal SiO as a probe of high velocity motions in regions of star formation

Journal Article · Fri Jan 01 04:00:00 EST 1982 · Astrophys. J., Lett. Ed.; (United States)

DOI:https://doi.org/10.1086/183713· OSTI ID:5427192

Downes, D; Genzel, R; Hjalmarson, A; Nyman, L A; Roennaeng, B

New observations of the v = 0, J = = 2..-->..1 line of SiO at 86.8 GHz show a close association of the thermal SiO emission and infrared and maser sources in regions of star formation. In addition to SiO emission with low velocity dispersion (..delta nu..< or =7 km s/sup -1/), we report the first detection of high velocity (''plateau'') emission toward W49 and W51. The low velocity SiO component may come from the core of the molecular cloud which contains the infrared and maser sources. The ''plateau'' may indicate mass clusters. In Orion KL, the positional centroid of the high velocity SiO emission (Vertical Bar..delta nu..Vertical Bar> or =20 km s/sup -1/) is near that of the component we identify as the ''18 km s/sup -1/ flow''. However, the centriods of the blue- and redshifted wings are displaced from each other by a few arcseconds, to the NW and NE of the position of the 18 km s/sup -1/ component. The mass-loss rates of the high velocity flow and the 18 km s/sup -1/ flow are similar.

• Research Organization: Institut de Radio Astronomie Millimetrique, B. P. 391, 38017
• OSTI ID: 5427192
• Journal Information: Astrophys. J., Lett. Ed.; (United States), Journal Name: Astrophys. J., Lett. Ed.; (United States) Vol. 252:1; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics &amp; Cosmology-- Stars &amp; Quasi-Stellar
Radio &amp; X-Ray Sources
640105 -- Astrophysics &amp; Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AMPLIFIERS
CHALCOGENIDES
ELECTRONIC EQUIPMENT
EMISSION
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EQUIPMENT
INTERSTELLAR GRAINS
MASERS
MICROWAVE AMPLIFIERS
MICROWAVE EQUIPMENT
NEBULAE
OXIDES
OXYGEN COMPOUNDS
PARTICLES
RADIAL VELOCITY
SILICON COMPOUNDS
SILICON OXIDES
SPECTRA
STAR ACCRETION
STAR EVOLUTION
VELOCITY