A three-dimensional extinction map of the Galactic anticentre from multiband photometry

TitleA three-dimensional extinction map of the Galactic anticentre from multiband photometry
Publication TypeJournal Article
Year of Publication2014
AuthorsChen, B-Q, Liu, X-W, Yuan, H-B, Zhang, H-H, Schultheis, M, Jiang, B-W, Huang, Y, Xiang, M-S, Zhao, H-B, Yao, J-S, Lu, H
Keywordsdust, extinction, Galaxy: disc, Galaxy: stellar content, Galaxy: structure

{We present a three-dimensional extinction map in the r band. The map has a spatial angular resolution, depending on latitude, between 3 and 9 arcmin and covers the entire Xuyi Schmidt Telescope Photometric Survey of the Galactic Anticentre (XSTPS-GAC) survey area of over 6000 deg$^{2}$ for Galactic longitude 140 łt} l łt} 240 deg and latitude -60 łt} b łt} 40 deg. By cross-matching the photometric catalogue of the XSTPS-GAC with those of 2MASS and WISE, we have built a multiband photometric stellar sample of about 30 million stars and applied spectral energy distribution (SED) fitting to the sample. By combining photometric data from the optical to the near-infrared, we are able to break the degeneracy between the intrinsic stellar colours and the amounts of extinction by dust grains for stars with high photometric accuracy, and trace the extinction as a function of distance for low Galactic latitude and thus highly extincted regions. This has allowed us to derive the best-fitting extinction and distance information of more than 13 million stars, which are used to construct the three-dimensional extinction map. We have also applied a Rayleigh-Jeans colour excess (RJCE) method to the data using the 2MASS and WISE colour (H - W2). The resulting RJCE extinction map is consistent with the integrated two-dimensional map deduced using the best-fitting SED algorithm. However for individual stars, the amounts of extinction yielded by the RJCE method suffer from larger errors than those given by the best-fitting SED algorithm. }