Astrophysics, abstract
astro-ph/0701146

From: Aaron Boley [view email]

Date: Fri, 5 Jan 2007 16:06:56 GMT (28kb)

The Internal Energy for Molecular Hydrogen in Gravitationally Unstable Protoplanetary Disks

Authors: Aaron C. Boley, Thomas W. Hartquist, Richard H. Durisen, Scott Michael

Comments: 13 pages, 3 figures. To appear in ApJL

The gas equation of state may be one of the critical factors for the disk instability theory of gas giant planet formation. This letter addresses the treatment of H$_2$ in hydrodynamical simulations of gravitationally unstable disks. In our discussion, we point out possible consequences of erroneous specific internal energy relations, approximate specific internal energy relations with discontinuities, and assumptions of constant $\Gamma_1$. In addition, we consider whether the ortho/para ratio for H$_2$ in protoplanetary disks should be treated dynamically as if the species are in equilibrium. Preliminary simulations indicate that the correct treatment is particularly critical for the study of gravitational instability when $T = 30$-50 K.

http://arxiv.org/abs/astro-ph/0701146