Mapping the Milky Way in 5-D with 170 Million Stars
Abstract
We present "augustus", a catalog of distance, extinction, and stellar parameter estimates to 170 million stars from and with drawing on a combination of optical to near-IR photometry from Pan-STARRS, 2MASS, UKIDSS, and unWISE along with parallax measurements from \textit{Gaia} DR2 and 3-D dust extinction maps. After applying quality cuts, we find 125 million objects have "high-quality" posteriors with statistical distance uncertainties of for objects with well-constrained stellar types. This is a substantial improvement over distance estimates derived from Gaia parallaxes alone and in line with results from previous work. We find the fits are able to accurately reproduce the de-reddened Gaia color-magnitude diagram, which serves as a useful consistency check of our results. We show that we are able to clearly detect large, kinematically-coherent substructures in our data relative to the input priors, including the Monoceros Ring and the Sagittarius stream, attesting to the quality of the catalog. Our results are publicly available at doi:10.7910/DVN/WYMSXV. An accompanying interactive visualization can be found at http://allsky.s3-website.us-east-2.amazonaws.com.
Cite
@article{arxiv.2503.02200,
title = {Mapping the Milky Way in 5-D with 170 Million Stars},
author = {Joshua S. Speagle and Catherine Zucker and Ana Bonaca and Phillip A. Cargile and Benjamin D. Johnson and Angus Beane and Charlie Conroy and Douglas P. Finkbeiner and Gregory M. Green and Harshil M. Kamdar and Rohan Naidu and Hans-Walter Rix and Edward F. Schlafly and Aaron Dotter and Gwendolyn Eadie and Daniel J. Eisenstein and Alyssa A. Goodman and Jiwon Jesse Han and Andrew K. Saydjari and Yuan-Sen Ting and Ioana A. Zelko},
journal= {arXiv preprint arXiv:2503.02200},
year = {2025}
}
Comments
Published in ApJ in 2024. 31 pages, 17 figures