Galactic Reddening in 3D from Stellar Photometry - An Improved Map

TL;DR

This paper introduces an improved 3D interstellar dust reddening map covering three quarters of the sky, derived from stellar photometry data of 800 million stars, with higher resolution and accuracy than previous maps.

Contribution

The authors develop a more precise 3D dust map using enhanced extinction laws and additional data, extending the reach and resolution of prior interstellar reddening maps.

Findings

Map agrees with far-infrared dust emission maps outside the Galactic plane.

Achieves a 10% mean scatter with Planck dust map after scale correction.

Traces dust to greater extinctions and higher angular resolutions.

Abstract

We present a new 3D map of interstellar dust reddening, covering three quarters of the sky (declinations greater than -30 degrees) out to a distance of several kiloparsecs. The map is based on high-quality stellar photometry of 800 million stars from Pan-STARRS 1 and 2MASS. We divide the sky into sightlines containing a few hundred stars each, and then infer stellar distances and types, along with the line-of-sight dust distribution. Our new map incorporates a more accurate average extinction law and an additional 1.5 years of Pan-STARRS 1 data, tracing dust to greater extinctions and at higher angular resolutions than our previous map. Out of the plane of the Galaxy, our map agrees well with 2D reddening maps derived from far-infrared dust emission. After accounting for a 15% difference in scale, we find a mean scatter of 10% between our map and the Planck far-infrared emission-based dust map, out to a depth of 0.8 mag in E(r-z), with the level of agreement varying over the sky. Our map can be downloaded at http://argonaut.skymaps.info, or by its DOI: 10.7910/DVN/LCYHJG.