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Further studies of gravitationally unstable protostellar disksModels of the solar nebula reveal that it might have been gravitationally unstable, both early and later in its evolution. Such instabilities produce density waves and associated gravitational torques, which are potent agents of angular momentum transport. In previous work, we conducted a series of numerical simulations designed to quantify the effects of gravitational instabilities in a generalizable way (Tomley, Cassen, & Steiman-Cameron 1991). Here we present a second series of simulations in which we examine disks of greater size, increased star/disk mass ratio, and flatter surface density distribution than those in our initial study. The purpose is to represent disks at a later stage of evolution than those already studied, to test the quantitative relations derived in our earlier work and to explore the effects of mass ratio on the results. The new results indicate that the tendencies for unstable, uncooled disks to heat to stability and for dynamical evolution rates to be proportional to cooling rates are general characteristics of the behavior of gravitationally unstable disks. Nevertheless, there are quantitative, and (for strong cooling) even qualitative differences that are revealed in the new simulations, particularly with regard to the cooling rates at which clumping tends to occur.
Document ID
19950036120
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Tomley, Leslie
(San Jose State Univ. San Jose, CA, United States)
Steiman-Cameron, Thomas Y.
(NASA Ames Research Center Moffett Field, CA, United States)
Cassen, Patrick
(NASA Ames Research Center Moffett Field, CA, United States)
Date Acquired
August 16, 2013
Publication Date
February 20, 1994
Publication Information
Publication: Astrophysical Journal, Part 1
Volume: 422
Issue: 2
ISSN: 0004-637X
Subject Category
Astrophysics
Accession Number
95A67719
Funding Number(s)
CONTRACT_GRANT: NCA2-556
CONTRACT_GRANT: NCA2-735
Distribution Limits
Public
Copyright
Other

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