Three-dimensional interstellar dust reddening maps of the Galactic plane

TL;DR

This paper introduces high-resolution 3D interstellar dust reddening maps of the Galactic plane using Gaia, 2MASS, and WISE data, employing machine learning to analyze over 56 million stars, revealing complex dust structures.

Contribution

It presents new 3D dust reddening maps with 6 arcmin resolution covering the entire Galactic plane, constructed through machine learning on multi-survey data, and provides empirical extinction coefficients.

Findings

Revealed the warped and complex structure of the Galactic dust disk.

Mapped dust features associated with Sagittarius, Local, and Perseus arms.

Provided empirical extinction coefficients for Gaia photometry.

Abstract

We present new three-dimensional (3D) interstellar dust reddening maps of the Galactic plane in three colours, E(G-Ks), E(Bp-Rp) and E(H-Ks). The maps have a spatial angular resolution of 6 arcmin and covers over 7000 deg$^2$ of the Galactic plane for Galactic longitude 0 deg $<$ $l$ $<$ 360 deg and latitude $|b|$ $<$ $10$ deg. The maps are constructed from robust parallax estimates from the Gaia Data Release 2 (Gaia DR2) combined with the high-quality optical photometry from the Gaia DR2 and the infrared photometry from the 2MASS and WISE surveys. We estimate the colour excesses, E(G-Ks), E(Bp-Rp) and E(H-Ks), of over 56 million stars with the machine learning algorithm Random Forest regression, using a training data set constructed from the large-scale spectroscopic surveys LAMOST, SEGUE and APOGEE. The results reveal the large-scale dust distribution in the Galactic disk, showing a number of features consistent with the earlier studies. The Galactic dust disk is clearly warped and show complex structures possibly spatially associated with the Sagittarius, Local and Perseus arms. We also provide the empirical extinction coefficients for the Gaia photometry that can be used to convert the colour excesses presented here to the line-of-sight extinction values in the Gaia photometric bands.