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Start Over Subject astrometry Validation Level 2
221. Gaia DR1 open cluster members
ID:
ivo://CDS.VizieR/J/A+A/601/A19
Title:
Gaia DR1 open cluster members
Short Name:
J/A+A/601/A19
Date:
21 Oct 2021
Publisher:
CDS
Description:
The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. . Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs.
222. Gaia DR3 source catalogue "light"
ID:
ivo://xaovo/gaia/q3/dr3lite
Title:
Gaia DR3 source catalogue "light"
Short Name:
gaia.dr3lite
Date:
25 Jun 2024 10:32:03
Publisher:
Xinjiang Astronomical Observatory,CAS
Description:
This is gaia_source from the Gaia Data Release 3, stripped to just enough columns to enable basic science (but therefore a bit faster and simpler to deal with than the full gaia_source table). Note that on this server, there is also The gedr3dist.main, which gives distances computed by Bailer-Jones et al. Use these in preference to working with the raw parallaxes. The full DR3 is available from numerous places in the VO (in particular from the TAP services ivo://uni-heidelberg.de/gaia/tap and ivo://esavo/gaia/tap).
223. Gaia DR3 source catalogue "light"
ID:
ivo://org.gavo.dc/gaia/q3/dr3lite
Title:
Gaia DR3 source catalogue "light"
Short Name:
gaia.dr3lite
Date:
27 Dec 2024 08:31:03
Publisher:
The GAVO DC team
Description:
This is gaia_source from the Gaia Data Release 3, stripped to just enough columns to enable basic science (but therefore a bit faster and simpler to deal with than the full gaia_source table). Note that on this server, there is also The gedr3dist.main, which gives distances computed by Bailer-Jones et al. Use these in preference to working with the raw parallaxes. This server also carries the gedr3mock schema containing a simulation of gaia_source based on a state-of-the-art galaxy model, computed by Rybizki et al. The full DR3 is available from numerous places in the VO (in particular from the TAP services ivo://uni-heidelberg.de/gaia/tap and ivo://esavo/gaia/tap).
224. Gaia DR2 source catalogue "light"
ID:
ivo://org.gavo.dc/gaia/q2/dr2light
Title:
Gaia DR2 source catalogue "light"
Short Name:
gaia.dr2light
Date:
27 Dec 2024 08:31:02
Publisher:
The GAVO DC team
Description:
This is a “light” version of the full Gaia DR2 gaia_source table, containing the original astrometric and photmetric columns with just enough additional information to let careful researchers notice when data is becomes uncertain and the full error model should be consulted. The full DR2 is available from numerous places in the VO (in particular from the TAP services ivo://uni-heidelberg.de/gaia/tap and ivo://esavo/gaia/tap). This table also includes a column containing the Renormalized Unit Weight Error RUWE (GAIA-C3-TN-LU-LL-124-01), a robust measure for the consistency of the solution. On this TAP service, there is the table gdr2dist.main containing distances computed by Bailer-Jones et al (:bibcode:`2018AJ....156...58B`). If in doubt, use these instead of the parallaxes provided here.
225. Gaia DR2 sources in GC and dSph
ID:
ivo://CDS.VizieR/J/A+A/616/A12
Title:
Gaia DR2 sources in GC and dSph
Short Name:
J/A+A/616/A12
Date:
21 Oct 2021
Publisher:
CDS
Description:
The goal of this paper is to demonstrate the outstanding quality of the second data release of the Gaia mission and its power for constraining many different aspects of the dynamics of the satellites of the Milky Way. We focus here on determining the proper motions of 75 Galactic globular clusters, nine dwarf spheroidal galaxies, one ultra-faint system, and the Large and Small Magellanic Clouds. Using data extracted from the Gaia archive, we derived the proper motions and parallaxes for these systems, as well as their uncertainties. We demonstrate that the errors, statistical and systematic, are relatively well understood. We integrated the orbits of these objects in three different Galactic potentials, and characterised their properties. We present the derived proper motions, space velocities, and characteristic orbital parameters in various tables to facilitate their use by the astronomical community. Our limited and straightforward analyses have allowed us for example to (i) determine absolute and very precise proper motions for globular clusters; (ii) detect clear rotation signatures in the proper motions of at least five globular clusters; (iii) show that the satellites of the Milky Way are all on high-inclination orbits, but that they do not share a single plane of motion; (iv) derive a lower limit for the mass of the Milky Way of 9.8^+6.7^_-2.7_x10^11^M_{sun}_ based on the assumption that the Leo~I dwarf spheroidal is bound; (v) derive a rotation curve for the Large Magellanic Cloud based solely on proper motions that is competitive with line-of-sight velocity curves, now using many orders of magnitude more sources; and (vi) unveil the dynamical effect of the bar on the motions of stars in the Large Magellanic Cloud. All these results highlight the incredible power of the Gaia astrometric mission, and in particular of its second data release.
226. Gaia DR2-WISE Galactic Plane Matches
ID:
ivo://CDS.VizieR/IV/35
Title:
Gaia DR2-WISE Galactic Plane Matches
Short Name:
IV/35
Date:
21 Oct 2021
Publisher:
CDS
Description:
Faint, hidden contaminants in the point-spread functions (PSFs) of stars cause shifts to their measured positions. Wilson & Naylor (2017MNRAS.468.2517W) showed failing to account for these shifts can lead to a drastic decrease in the number of returned catalogue matches in crowded fields. Here we highlight the effect these perturbations have on cross-matching, for matches between Gaia DR2 and WISE stars in a crowded Galactic plane region. Applying the uncertainties as quoted to Gaussian-based astrometric uncertainty functions (AUFs) can lead, in dense Galactic fields, to only matching 55% of the counterparts. We describe the construction of empirical descriptions for AUFs, building on the cross-matching method of Wilson & Naylor (2018MNRAS.473.5570W), utilising the magnitudes of both catalogues to discriminate between true and false counterparts. We apply the improved cross-matching method to the Galactic plane |b|<10. We provide the most likely counterpart matches and their respective probabilities. We also analyse several cases to verify the robustness of the results, highlighting some important caveats and considerations. Finally, we discuss the effect PSF resolution has by comparing the intra- catalogue nearest neighbour separation distributions of a sample of likely contaminated WISE objects and their corresponding Spitzer counterpart. We show that some WISE contaminants are resolved in Spitzer, with smaller intra-catalogue separations. We have highlighted the effect contaminant stars have on WISE, but it is important for all photometric catalogues, playing an important role in the next generation of surveys, such as LSST.
227. Gaia EDR3
ID:
ivo://CDS.VizieR/I/350
Title:
Gaia EDR3
Short Name:
I/350
Date:
18 Jan 2022 09:31:17
Publisher:
CDS
Description:
Gaia DR3 data (both Gaia EDR3 and the full Gaia DR3) are based on data collected between 25 July 2014 (10:30 UTC) and 28 May 2017 (08:44 UTC), spanning a period of 34 months. As a comparison, Gaia DR2 was based on 22 months of data and Gaia DR1 was based on observations collected during the first 14 months of Gaia's routine operational phase. Survey completeness: The Gaia EDR3 catalogue is essentially complete between G=12 and G=17. The source list for the release is incomplete at the bright end and has an ill-defined faint magnitude limit, which depends on celestial position. The combination of the Gaia scan law coverage and the filtering on data quality which will be done prior to the publication of Gaia EDR3, does lead to some regions of the sky displaying source density fluctuations that reflect the scan law pattern. In addition, small gaps exist in the source distribution, for instance close to bright stars. Astrometry: The parallax improvement is typically 20% with respect to Gaia DR2. The proper motions are typically a factor two better than in Gaia DR2. An overall reduction of systematics has been achieved. E.g., the parallax zero point deduced from the extragalactic sources is about -20{mu}as. A tentative correction formula for the parallax zero point will be provided. Closer to the release date of Gaia Early Data Release 3, an update will be given on the astrometry. Photometry: The G-band photometric uncertainties are ~0.25mmag for G<13, 1mmag at G=17, and 5mmag at G=20mag. The GBP-band photometric uncertainties are ~1mmag for G<13, 10mmag at G=17, and 100mmag at G=20mag. The GRP-band photometric uncertainties are ~1mmag for G<13, 5mmag at G=17, and 50mmag at G=20mag. Closer to the release date of Gaia Early Data Release 3, an update will be given on the photometry. Gaia EDR3 does not contain new radial velocities. The radial velocities of Gaia Data Release 2 have been added to Gaia EDR3 in order to ease the combination of spectrosopic and astrometric data. Radial velocities: Gaia EDR3 hence contains Gaia DR2 median radial velocities for about 7.21 million stars with a mean G magnitude between ~4 and ~13 and an effective temperature (Teff) in the range ~3550 to 6900K. The overall precision of the radial velocities at the bright end is of the order of ~200-300m/s while at the faint end, the overall precision is ~1.2km/s for a Teff of 4750K and ~3.5km/s for a Teff of 6500K. Before publication in Gaia EDR3, an additional filtering has been performed onto the Gaia DR2 radial velocities to remove some 4000 sources that had wrong radial velocities. Please be aware that the Gaia DR2 values are assigned to the Gaia EDR3 sources through an internal cross-match operation. In total, ~10000 Gaia DR2 radial velocities could not be associated to a Gaia EDR3 source. Astrophysical parameters: Gaia EDR3 does not contain new astrophysical parameters. Astrophysical parameters have been published in Gaia DR2 and a new set is expected to be released with the full Gaia DR3 release. Variable stars: Gaia EDR3 does not contain newly classified variable stars. For the overview of the currently available variable stars from Gaia DR2, have a look here. Classifications for a larger set of variable stars are expected with the full Gaia DR3 release. Solar system objects: A large set of solar system objects with orbits will become available with the full Gaia DR3 release. Information on the currently available asteroids in Gaia DR2 can be found here. Documentation: Data release documentation is provided along with each data release in the form of a downloadable PDF and a webpage. The various chapters of the documentation have been indexed at ADS allowing them to be cited. Please visit the Gaia Archive (https://gea.esac.esa.int/archive) to access this documentation, and make sure to check out all relevant information given through the documentation overview page (https://www.cosmos.esa.int/web/gaia-users/archive).
228. Gaia eDR3 Autocorrelation
ID:
ivo://org.gavo.dc/gedr3auto/q/main
Title:
Gaia eDR3 Autocorrelation
Short Name:
gedr3auto.main
Date:
27 Dec 2024 08:31:05
Publisher:
The GAVO DC team
Description:
This is a table that simply gives, for each object in Gaia eDR3, the identifier of its closest neighbour together with the distance of the pair.
229. Gaia-FUN-SSO network. Apophis campaign
ID:
ivo://CDS.VizieR/J/A+A/583/A59
Title:
Gaia-FUN-SSO network. Apophis campaign
Short Name:
J/A+A/583/A59
Date:
21 Oct 2021
Publisher:
CDS
Description:
Astrometric observations performed by the Gaia Follow-Up Network for Solar System Objects (Gaia-FUN-SSO) play a key role in ensuring that moving objects first detected by ESA's Gaia mission remain recoverable after their discovery. An observation campaign on the potentially hazardous asteroid (99942) Apophis was conducted during the asteroid's latest period of visibility, from 12/21/2012 to 5/2/2013, to test the coordination and evaluate the overall performance of the Gaia-FUN-SSO . The 2732 high quality astrometric observations acquired during the Gaia-FUN-SSO campaign were reduced with the Platform for Reduction of Astronomical Images Automatically (PRAIA), using the USNO CCD Astrograph Catalogue 4 (UCAC4, Cat. I/322) as a reference. The astrometric reduction process and the precision of the newly obtained measurements are discussed. We compare the residuals of astrometric observations that we obtained using this reduction process to data sets that were individually reduced by observers and accepted by the Minor Planet Center.
230. Gaia GraL. III. New lensed systems
ID:
ivo://CDS.VizieR/J/A+A/622/A165
Title:
Gaia GraL. III. New lensed systems
Short Name:
J/A+A/622/A165
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Gaia GraL catalogue of clusters is composed of 2,129,659 clusters consisting of three or four stationary sources from Gaia DR2. Each cluster is assigned a discriminant value, called the extremely randomized trees probability, that reflects its ability to be matched to the image positions and relative magnitudes produced through simulations of gravitational lens systems.

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