The PS1 survey provides 5 band photometry on millions of stars in our Galaxy. This photometry allows the distance and reddening to every star to be estimated individually. This data set has the potential to dramatically advance our knowledge of the 3D structure of the Galaxy's dust.

Locations and distances of major molecular clouds

We have undertaken an effort to extract as much information as possible from this rich data set. Among the first results of this effort is a catalog of distances to the major high latitude and outer Galaxy molecular clouds. By avoiding the inner Galaxy, we are able to focus on parts of the sky where the entire dust column is dominated by a single cloud, simplifying the modeling of the generally extremely complicated distribution of dust in the Galaxy.

Specifically, we have estimated the distances to dust clouds toward stars in Canis Major, California, Cepheus, Hercules, Lacerta, Monoceros, Orion, Pegasus, Perseus, Polaris, Taurus, and Ursa Major. We have additionally estimated the distances to most of the clouds from the Magnani, Blitz, and Mundy (1985) catalog of high latitude molecular clouds, excluding a small number which lie outside the PS1 footprint or contain little dust.

The plot at right shows our distance estimates (bottom panel) to clouds along sight lines (top panel) through the Galaxy. Horizontal lines indicate literature estimates to the cloud in question. In general we find good agreement, though we substantially revise distance estimates to Ursa Major and Polaris, and we are aware of no estimates of the distance to clouds in Camelopardis, Pegasus, Hercules, and Aquila South.