Gaia Data Release 3: Summary of the content and survey properties

TL;DR

Gaia DR3 significantly expands the Gaia data ecosystem beyond DR2/EDR3 by delivering vast new spectroscopic, photometric, and astrometric products, including mean RVS and BP/RP spectra, radial velocities for tens of millions of stars, extensive astrophysical parameters, and a comprehensive non-single star, solar system, and extragalactic content. The release is underpinned by substantial data-processing enhancements, refined calibrations, and extensive quality assessments, with robust tools for synthetic photometry and data access. DR3 enables wide-ranging science—from precise Galactic structure and chemo-dynamical maps to all-sky QSO/galaxy profiling and asteroid reflectance studies—while clearly outlining limitations and caveats to guide users. Looking forward, Gaia DR4/DR5 will deliver full time-series data and even more expansive astrophysical characterizations, further increasing Gaia's scientific impact.

Abstract

We present the third data release of the European Space Agency's Gaia mission, GDR3. The GDR3 catalogue is the outcome of the processing of raw data collected with the Gaia instruments during the first 34 months of the mission by the Gaia Data Processing and Analysis Consortium. The GDR3 catalogue contains the same source list, celestial positions, proper motions, parallaxes, and broad band photometry in the G, G$_{BP}$, and G$_{RP}$ pass-bands already present in the Early Third Data Release. GDR3 introduces an impressive wealth of new data products. More than 33 million objects in the ranges $G_{rvs} < 14$ and $3100 <T_{eff} <14500 $, have new determinations of their mean radial velocities based on data collected by Gaia. We provide G$_{rvs}$ magnitudes for most sources with radial velocities, and a line broadening parameter is listed for a subset of these. Mean Gaia spectra are made available to the community. The GDR3 catalogue includes about 1 million mean spectra from the radial velocity spectrometer, and about 220 million low-resolution blue and red prism photometer BPRP mean spectra. The results of the analysis of epoch photometry are provided for some 10 million sources across 24 variability types. GDR3 includes astrophysical parameters and source class probabilities for about 470 million and 1500 million sources, respectively, including stars, galaxies, and quasars. Orbital elements and trend parameters are provided for some $800\,000$ astrometric, spectroscopic and eclipsing binaries. More than $150\,000$ Solar System objects, including new discoveries, with preliminary orbital solutions and individual epoch observations are part of this release. Reflectance spectra derived from the epoch BPRP spectral data are published for about 60\,000 asteroids. Finally, an additional data set is provided, namely the Gaia Andromeda Photometric Survey (abridged)

Figures (2)

• Figure 1: Distribution of the mean values of $G$ for the main Gaia DR3 components shown as histograms with bins of $0.1$ mag in width. The top panel shows the histograms for the basic observational data in Gaia DR3 (spectra, radial velocities, $v_\mathrm{broad}$, photometric time series). The middle panel shows histograms for the stellar astrophysical contents, and the bottom panel shows the non-stellar astrophysical contents. The sharp transitions in the top and middle panels at $G=17.65$ and $G=19$ are caused by the limit on the brightness of sources for which BP/RP spectra are published and the limit up to which astrophysical parameters were estimated. The SSO histogram shows the distribution of the transit-level $G$-band magnitudes DR3-DPACP-150. The QSO and galaxy candidate histograms extend to very bright magnitudes which is a consequence of favouring completeness over purity in these samples, and not applying any filtering to remove them DR3-DPACP-101.
• Figure 2: Uncertainties on the astrometric parameters vs. $G$ for Gaia data releases 1--3 and for the future releases Gaia DR4 and Gaia DR5. The panels show from top to bottom the uncertainties in parallax, proper motion in Right Ascension, and proper motion in Declination. The uncertainties for Gaia DR1 refer to the Tycho-Gaia Astrometric Solution and are shown in the form of density maps, with lighter colours indicating a higher density of sources. The two distinct low-uncertainty elliptical regions in the Gaia DR1 proper motion uncertainties are due to stars for which the Hipparcos and Gaia positions could be combined to derive proper motions over a 24-year time baseline. The proper motion uncertainties for Gaia DR3, based on only a 34 month time baseline are comparable or even slightly better.