Gaia Data Release 2

By Frédéric Arenou, X. Luri, C. Babusiaux, C. Fabricius, A. Helmi, T. Muraveva, Annie Robin, Federica Spoto, Antonella Vallenari, T. Antoja and 29 more. Astronomy & Astrophysics, 2018

253 citations recorded by the source corpus.

Context. The second Gaia data release (DR2) contains very precise astrometric and photometric properties for more than one billion sources, astrophysical parameters for dozens of millions, radial velocities for millions, variability information for half a million stars from selected variability classes, and orbits for thousands of solar system objects. Aims. Before the catalogue was published, these data have undergone dedicated validation processes. The goal of this paper is to describe the validation results in terms of completeness, accuracy, and precision of the various Gaia DR2 data. Methods. The validation processes include a systematic analysis of the catalogue content to detect anomalies, either individual errors or statistical properties, using statistical analysis and comparisons to external data or to models. Results. Although the astrometric, photometric, and spectroscopic data are of unprecedented quality and quantity, it is shown that the data cannot be used without dedicated attention to the limitations described here, in the catalogue documentation and in accompanying papers. We place special emphasis on the caveats for the statistical use of the data in scientific exploitation. In particular, we discuss the quality filters and the consideration of the properties, systematics, and uncertainties from astrometry to astrophysical parameters, together with the various selection functions.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/d687bf2bb339a4fb038b39de1a23e4fda9f97d6e

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Citations in the corpus

Gaia Data Release 2 (2018, methodology): “The processed data was submitted to extensive validation prior to publication, as detailed in Arenou et al. (2018).”
A Gaia DR2 view of the open cluster population in the Milky Way (2018, methodology): “It is also compatible with the values quoted by Arenou et al. (2018) who assessed the zero point with a variety of reference tracers.”
Milky Way Cepheid Standards for Measuring Cosmic Distances and Application to Gaia DR2: Implications for the Hubble Constant (2018, background): “The online documentation also indicates that the estimated parallax zeropoint depends on the sample of sources examined (Arenou et al. 2018), and the value determined in L18 should not be used to “correct” the catalog parallax values.”
Stellar and substellar companions of nearby stars from Gaia DR2 (2018, methodology): “This global offset correction was derived by Lindegren et al. (2018) and Arenou et al. (2018) (see also Sahlholdt & Silva Aguirre 2018) from QSOs fainter than G = 17.”
The Gaia–Kepler Stellar Properties Catalog. I. Homogeneous Fundamental Properties for 186,301 Kepler Stars (2020, unknown): “Typical errors are on the order of 0.05 dex, which is a dramatic improvement over the ≈ 0.2 dex log g median error provided in Mathur et al. (2017) due to the strong radius constraints from Gaia DR2 parallaxes.”
Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18 (2019, methodology): “Colour excess factor flag: Evans et al. (2018) and Arenou et al. (2018) recommend the use of the phot_bp_rp_excess_factor to flag spurious Gaia DR2 photometry.”
A buyer’s guide to the Hubble constant (2021, unknown): “The average of the quasar parallaxes in it is -29µas (negative parallaxes can happen when position measurement error is larger than the parallax), and there were indications this “zero point” may vary with stellar colour, luminosity and position on the sky (Arenou et al. 2018).”
Gaia Data Release 2 (2018, background): “In some cases, this is known to produce spurious results, for instance, very large positive or negative parallaxes (Arenou et al. 2018; see also Appendix C).”
Painting a portrait of the Galactic disc with its stellar clusters (2020, methodology): “…for the uncertainties in the mean parallax, the local parallax zero-point variation, and to simulate the known zero-point offset in parallaxes (Lindegren et al. 2018; Arenou et al. 2018), we then subtracted 0.029 mas and added a random offset that was uniformly picked between −0.05 and +0.05 mas.”