Gaia Data Release 3: Summary of the content and survey properties (2208.00211v1)

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)

• The paper introduces Gaia DR3, delivering enhanced astrometric and spectroscopic measurements for approximately 1.8 billion sources and over 33 million stars.
• It details new low-resolution BP/RP spectra, a comprehensive variable star catalog, and extensive non-single star data, significantly deepening astrophysical insights.
• Enhanced measurements for solar system objects and refined astrophysical parameters provide a robust framework for advancing models of stellar and galactic evolution.

Summary of the Gaia Data Release 3

The paper presents the third data release (DR3) of the European Space Agency's Gaia mission, which constitutes a substantial increment in the breadth and depth of astrophysical information available to the scientific community. The Gaia DR3 includes a variety of new data products, significantly expanding upon previous releases both in scope and detail.

Main Enhancements and Data Products

1. Astrometric Data: DR3 sustains the high precision of astrometric data from earlier releases, encompassing positions, proper motions, and parallaxes. However, a significant addition is the astrometry for approximately 1.8 billion sources, which underpins many of the derived astrophysical parameters.
2. Radial Velocity Measurements: A notable advancement is the extension of radial velocity measurements to over 33 million stars. Dramatically increased from previous data releases, these measurements now encompass faint stars down to \textit{G_RVS} = 14 and a broader range of temperatures (3100-14500 K).
3. Photometric Data: The release includes extensive low-resolution BP/RP spectra for about 220 million sources, allowing the extraction of finer astrophysical parameters. The photometric content is complemented with the addition of \textit{G_RVS} magnitudes.
4. Variable Stars Catalog: Gaia DR3 identifies over 10 million variable sources across numerous types, utilizing time-series data to classify and characterize variability with high precision, thus providing crucial insights into stellar evolution.
5. Non-Single Stars (NSS): The catalog contains data on approximately 800,000 non-single star systems, markedly surpassing previous datasets in terms of richness and detail, covering astrometric, spectroscopic, and eclipsing binaries.
6. Solar System Objects (SSOs): Amazingly precise astrometric measurements for over 150,000 asteroids are provided, along with spectro-photometric data facilitating the paper of these objects’ surfaces.
7. Astrophysical Parameters: The release contains a wealth of data on stellar and non-stellar objects. Astrophysical parameters include temperatures, masses, ages, and chemical compositions for millions of stars, as well as a refined classification of extragalactic objects.

Implications and Future Directions

The wealth of data released with Gaia DR3 represents a significant augmentation of the existing astronomical datasets. By improving both the quantity and quality of available data, Gaia DR3 allows for the profound exploration of stellar dynamics, star formation, galactic structures, and cosmology. The implications of such comprehensive datasets extend into various domains of astrophysics, enhancing models of stellar and galactic evolution.

The success and utility of Gaia DR3 set the stage for future data releases that promise even greater precision and temporal depth, with anticipated advances including epoch astrometry and photometry. Such enhancements will undoubtedly catalyze further breakthroughs and underpin novel research across the astronomical sciences.

In summary, Gaia DR3 amalgamates a formidable array of observations and analyses that stand to significantly refine our understanding of the cosmos, showcasing the capacity of large-scale space missions to drive forward astrophysical discovery in a profound, lasting manner.