Copyright by Athena Ranice Stacy 2011 - The University of Texas at ...

sink tform [yr] Mfinal [M⊙] rinit [AU] rfinal [AU]
1 0 27 0 0
2 300 0.9 100 2330
3 2000 2.75 70 83
Table 3.1: Formation times, final masses, distances from the main sink upon
initial formation, and distances from the main sink at the final simulation
output in the ‘no-feedback’ case. We include the sinks still present at the end
of the simulation (5000 yr).
sink tform [yr] Mfinal [M⊙] rinit [AU] rfinal [AU]
1 0 15.9 0 0
2 200 5.6 110 470
Table 3.2: Same as Table 3.1, but for sinks remaining at the end of the ‘withfeedback’
case at 4200 yr..
approximate κ to be 3 × 10 −11 s −1 , so Q ∼ 0.2, easily satisfying the Toomre
criterion.
Figures 3.5 and 3.6 show the density and temperature morphology
within the central 10,000 AU. The multiple sinks and clumpy disk structure
are easily visible here, as expected from the low Toomre parameter, though the
particular shape of the disk in each case is very different. The ‘no-feedback’
case has a clearly visible bifurcated temperature structure, with a cool disk
and surrounded by warm gas. The ‘with-feedback’ also has cool disk gas, but
the central region is much more dominated by an hour-glass shaped bubble of
hot gas.
As discussed in Kratter et al. (2010), the actual minimum value of Q
can vary with disk properties such as scale height, and from Figures 3.5 and 3.6
we see this varies throughout the disk evolution for both cases. Thus, it is also
necessary to consider other disk properties, particularly the infall rate of mass
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