A Gaia DR2 Mock Stellar Catalog

TL;DR

This paper introduces a realistic mock catalog of Milky Way stars modeled after Gaia DR2, enabling testing, calibration, and comparison of galactic data analysis methods.

Contribution

The authors created a comprehensive, Gaia DR2-matching stellar catalog using Galaxia and dust maps, including detailed stellar parameters and uncertainties.

Findings

Catalog mimics Gaia DR2 data structure and content

Enables realistic testing and comparison of galactic models

Accessible via virtual observatory with query capabilities

Abstract

We present a mock catalog of Milky Way stars, matching in volume and depth the content of the Gaia data release 2 (GDR2). We generated our catalog using Galaxia, a tool to sample stars from a Besancon Galactic model, together with a realistic 3D dust extinction map. The catalog mimicks the complete GDR2 data model and contains most of the entries in the Gaia source catalog: 5-parameter astrometry, 3-band photometry, radial velocities, stellar parameters, and associated scaled nominal uncertainty estimates. In addition, we supplemented the catalog with extinctions and photometry for non-Gaia bands. This catalog can be used to prepare GDR2 queries in a realistic runtime environment, and it can serve as a Galactic model against which to compare the actual GDR2 data in the space of observables. The catalog is hosted through the virtual observatory GAVO's Heidelberg data center service and thus can be queried using ADQL as for GDR2 data.