Hot and cold gas toward young stellar objects

Journal Article · Thu Nov 01 04:00:00 EST 1990 · Astrophysical Journal; (USA)

DOI:https://doi.org/10.1086/169365· OSTI ID:6062554

Mitchell, G F; Maillard, J; Allen, M; Beer, R; Belcourt, K ^[1]

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1. Saint Mary's Univ., Halifax (Canada) Canada-France-Hawaii Telescope Corp., Waimea, HI (USA) CNRS, Institut d'Astrophysique, Paris (France) JPL, Pasadena, CA (USA)

High-resolution M band spectra are presented for the seven embedded IR sources W3 IRS 5, S140 IRS1, NGC 7538 IRS 1, NGC 7538 IRS 9, GL 2136, LkH-alpha 101, and MWC 349A, and the data are combined with previously published work for W33A and GL 2591. Cold CO is seen toward all nine sources, with temperatures from 11 K to 66 K. Column densities of cold CO are presented. Hot gas is seen toward eight of the nine objects with temperatures from 120 K to 1010 K. New lower limits to the hot gas density are obtained. The hot gas toward GL 2591, GL 2136, W3 IRS 5, and S140 IRS 1 is probably very near the central source and heated via gas-grain collisions. The optical depth in the silicate feature is strongly correlated with the (C-13)O column density, confirming that silicate optical depth is a useful measure of gas column density. The ratio of solid-to-gaseous CO is obtained for seven sources. 43 refs.

• OSTI ID: 6062554
• Journal Information: Astrophysical Journal; (USA), Journal Name: Astrophysical Journal; (USA) Vol. 363; ISSN ASJOA; ISSN 0004-637X
• 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
ABUNDANCE
COLLISIONS
COSMIC GASES
DENSITY
ELECTROMAGNETIC RADIATION
ELEMENT ABUNDANCE
EMISSION SPECTRA
ENERGY-LEVEL TRANSITIONS
EXCITATION
FLUIDS
GASES
HEATING
HIGH TEMPERATURE
INFRARED RADIATION
INTERSTELLAR GRAINS
INTERSTELLAR SPACE
LINE WIDTHS
MOLECULES
OXYGEN COMPOUNDS
PARTICLES
PHYSICAL PROPERTIES
PROTOSTARS
RADIATIONS
SILICATES
SILICON COMPOUNDS
SPACE
SPECTRA