Krumholz Model Fitting
By Elijah Bernstein-Cooper, September 15, 2015, 0 comments.

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Krumholz Model Fitting

I successfully fit both the Krumholz and Sternberg models to the HI vs. H surface density relationship in each of the cores. The $\phi_{\rm CNM}$ values for the Krumholz model are all near 10. I will post the distribution of the fitted model parameters for the model tomorrow.

The figure below shows the HI vs. H distribution in the form of a contour plot. The shaded orange lines show the distribution of fitted models within the monte carlo simulation. We can see that the $\Sigma_{HI}$ threshold varies by about 50% for California cores, and much less for Perseus cores.


California

Taurus

Perseus

Figure 1

HI vs H surface density distributions for cores in Taurus Perseus and California. The orange lines show the distribution of Krumholz et al. (2009) model fits.


N(HI) vs. $A_V$ Distributions

The $A_V$ values have changed since the last iteration. Now the $A_V$ is shown as the most common $A_V$ values of the bootstrap simulation. We are scaling the Planck $A_V$ by a random uniform scalar between the fitted Planck / 2MASS slope and 1. Hence our best estimate of the scalar for the Planck data will be the average slope between the Planck / 2MASS slope and 1. This means the Planck $A_V$ is divided by about 1.2 for each cloud. This leads to a more reasonable-looking fit between N(HI) and $A_V$ in California. Note, this does not change the fitted DGR, only the display $A_V$ distribution.


Figure 2

N(HI) vs. $A_V$ distributions.