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Infrared spectra of protostellar collapseTheoretical models of the formation of low mass stars by cloud collapse predict that OI(63 micrometers) and IR rotational lines of CO and H2O dominate the cooling in the freefalling region 10-1000 AU from the protostar. The freefalling gas supersonically hits the protoplanetary disk orbiting the protostar, forming an accretion shock with strong IR emission in rotational lines of H2O and OH, and OI(63 microns). The accretion shock spectra and line profiles depend on the mass flux through the shock and the typical distance r-bar at which the freefalling gas strikes the disk. The line widths are of order the Keplerian speed, or approx. 10(r-bar/10AU)(exp -0.5) km/s, for the accretion shock lines, and less for the lines from the infalling gas. Measurements of the IR line fluxes and profiles from the freefalling gas and the accretion shock diagnoses how a protostar and disk are formed and requires high sensitivity and high spectral and spatial resolving power. SOFIA will be the optimum observatory for many of these lines, although ISO will contribute and the KAO may make a few pioneering detections.
Document ID
19960003645
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Hollenbach, David J.
(NASA Ames Research Center Moffett Field, CA, United States)
Ceccarelli, Cecilia
(NASA Ames Research Center Moffett Field, CA, United States)
Neufeld, David A.
(NASA Ames Research Center Moffett Field, CA, United States)
Tielens, Alexander G. G. M.
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
September 6, 2013
Publication Date
January 1, 1995
Publication Information
Publication: Astronomical Society of the Pacific, Airborne Astronomy Symposium on the Galactic Ecosystem: From Gas to Stars to Dust, Volume 73
Subject Category
Astronomy
Accession Number
96N13655
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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