3D Reddening and Extinction Maps at the Beginning of the Gaia Era

TL;DR

This paper compares eight detailed 3D reddening and extinction maps within 1200 pc of the Sun, providing correction formulas and catalogues to improve Gaia DR1 star distance measurements.

Contribution

It introduces a comprehensive comparison of existing 3D reddening maps, derives correction formulas for overestimated and minimal reddening, and compiles extensive reddening catalogues for Gaia stars.

Findings

Correction formulas for reddening overestimation and minimal reddening.

Comparison of eight 3D reddening maps reveals differences and biases.

Catalogues of reddening for over 630,000 cells and 1.75 million stars.

Abstract

The vast majority of Gaia DR1 Tycho-Gaia astrometric solution (TGAS) stars are located within a distance of 1200 pc from the Sun and up to 600 pc within the Galactic plane. Complete usage of their parallaxes is possible only if their reddening and interstellar extinction are known. We obtained those from a comparison of the eight most accurate and complete 3D maps of reddening and extinction in the considered space. We analyzed the statistics of the maps and their differences in the cells of $20\times20\times20$ pc in the whole considered space. The comparison of the maps in the cells outside the dust layer allows us to obtain a formula of the correction for both overestimated and minimal reddenings of the SFD map through the dust half-layer. We point out the need for a further study of the minimal reddening through the dust half-layer and the overestimation of higher reddenings by use of the most precise data. Based on the data of all the maps under consideration we compile two catalogues of the reddenings: for 630,109 cells of $20\times20\times20$ pc in the considered space and for 1,758,723 TGAS stars with the most accurate distances.