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Photoevaporation of Disks Around Young StarsYoung massive stars produce sufficient Lyman continuum luminosity phi to have a significant effect on the structure and evolution of the accretion disks surrounding diem. We show that inside a critical disk radius r(sub g), an isothermal 10(exp 4) K atmosphere forms with a scale height that increases with r(sup3/2) for r less than or equal to r(sub g). For r less than or equal to r(sub g), the diffuse field caused by hydrogen recombinations to the ground state in the atmosphere produces a steadily evaporating disk. The mass loss from this outer region of the disk is of order 10(exp -5) Mo/yr phi(sub 49)1/2, where phi(sub 49) is defined as phi/10(exp 49) photons/s. The mass loss has two important consequences. First, the slow (10-50 km/s) wind that results may explain the long life of unresolved ultracompact HII regions. Secondly, the dependence on phi implies that accretion through the disk onto the star will be quenched once the photoevaporation rate exceeds the accretion rate. This may act to limit the mass of the forming star.
Document ID
20010047001
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Hollenbach, David
(NASA Ames Research Center Moffett Field, CA United States)
Morrison, David
Date Acquired
August 20, 2013
Publication Date
January 1, 1994
Subject Category
Astrophysics
Funding Number(s)
PROJECT: RTOP 188-44-53
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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