By Elijah Bernstein-Cooper, July 13, 2015, 0 comments.

The masking routine is likely complete now. Below are the likelihood spaces. These seem to estimate a reasonable amount of error in all three parameters. The derived $HI$ width is near the 10 km/s width found by Lee et al. (2012) (see figure 3), who found the $HI$ width which produced the best-correlated $N(HI)$ with the dust column density is around 10 km/s. Lee et al. (2012) adopted a 20 km/s $HI$ width, corresponding to the FWHM of the correlation, leading to higher $N(HI)$. In our analysis, we find an intercept and a smaller width better fit the dust column density. The DGRs in our analysis and Lee et al. (2012) are consistent with each other.

I am using the IRIS $A_V$ image from Lee et al. (2012), and binning the data to 30$^\prime$ pixel sizes for the entire analysis to avoid correlated errors from the CIB.

Figure 1. - The left column represents the initial masking performed with a $HI$ width of $70$ km/s to create the initial $N(HI)$ map used in masking, the right, an HI width of $13$ km/s.