All-sky three-dimensional dust density and extinction Maps of the Milky Way out to 2.8 kpc

TL;DR

This paper introduces high-resolution, all-sky 3D dust density and extinction maps of the Milky Way out to 2.8 kpc, utilizing a scalable Gaussian Process algorithm and extensive Gaia, 2MASS, and AllWISE data.

Contribution

The authors develop a fast, scalable method to produce detailed 3D dust maps combining optical and infrared data, covering large sky areas at parsec-scale resolution.

Findings

Maps agree with previous studies at a 0.001 mag/pc scale.

Recovered known Galactic features and identified a potential inter-arm gap.

Maps reveal a large under-density near the Galactic Centre.

Abstract

Three-dimensional dust density maps are crucial for understanding the structure of the interstellar medium of the Milky Way and the processes that shape it. However, constructing these maps requires large datasets and the methods used to analyse them are computationally expensive and difficult to scale up. As a result it is has only recently become possible to map kiloparsec-scale regions of our Galaxy at parsec-scale grid sampling. We present all-sky three-dimensional dust density and extinction maps of the Milky Way out to 2.8~kpc in distance from the Sun using the fast and scalable Gaussian Process algorithm \DustT. The sampling of the three-dimensional map is $l,b,d = 1^{\circ} \times1^{\circ} \times 1.7$~pc. The input extinction and distance catalogue contains 120 million stars with photometry and astrometry from Gaia DR2, 2MASS and AllWISE. This combines the strengths of optical and infrared data to probe deeper into the dusty regions of the Milky Way. We compare our maps with other published 3D dust maps. All maps quantitatively agree at the $0.001$~mag~pc$^{-1}$ scale with many qualitatively similar features, although each map also has its own features. We recover Galactic features previously identified in the literature. Moreover, we also see a large under-density that may correspond to an inter-arm or -spur gap towards the Galactic Centre.