J/A+A/653/A160 Updated radial velocities from Gaia DR2 (Seabroke+, 2021)
Gaia Early Data Release 3. Updated radial velocities from Gaia DR2.
Seabroke G.M., Fabricius C., Teyssier D., Sartoretti P., Katz D.,
Cropper M., Antoja T., Benson K., Smith M., Dolding C., Gosset E.,
Panuzzo P., Thevenin F., Allende Prieto C., Blomme R., Guerrier A.,
Huckle H., Jean-Antoine A., Haigron R., Marchal O., Baker S., Damerdji Y.,
David M., Fremat Y., Janssen K., Jasniewicz G., Lobel A., Samaras N.,
Plum G., Soubiran C., Vanel O., Zwitter T., Ajaj M., Caffau E., Chemin L.,
Royer F., Brouillet N., Crifo F., Guy L.P., Hambly N.C., Leclerc N.,
Mastrobuono-Battisti A., Viala Y.
<Astron. Astrophys., 653, A160 (2021)>
=2021A&A...653A.160S 2021A&A...653A.160S (SIMBAD/NED BibCode)
ADC_Keywords: Stars, nearby ; Radial velocities ; Optical
Keywords: space vehicles: instruments - instrumentation: spectrographs -
techniques: radial velocities - techniques: spectroscopic
Abstract:
Gaia's Early Third Data Release (EDR3) does not contain new radial
velocities because these will be published in Gaia's full third data
release (DR3), expected in the first half of 2022. To maximise the
usefulness of EDR3, Gaia's second data release (DR2) sources (with
radial velocities) are matched to EDR3 sources to allow their DR2
radial velocities to also be included in EDR3. This presents two
considerations: (i) a list of 70365 sources with potentially
contaminated DR2 radial velocities has been published; and (ii) EDR3
is based on a new astrometric solution and a new source list, which
means sources in DR2 may not be in EDR3.
The two aims of this work are: (i) investigate the list in order to
improve the DR2 radial velocities being included in EDR3 and to avoid
false-positive hypervelocity candidates; and (ii) match the DR2
sources (with radial velocities) to EDR3 sources. Methods. Thetwo
methods of this work are: (i) unpublished, preliminary DR3 radial
velocities of sources on the list, and high-velocity stars not on the
list, are compared with their DR2 radial velocities to identify and
remove contaminated DR2 radial velocities from EDR3; and (ii) proper
motions and epoch position propagation is used to attempt to match all
sources with radial velocities in DR2 to EDR3 sources. The comparison
of DR2 and DR3 radial velocities is used to resolve match ambiguities.
EDR3 contains 7209831 sources with a DR2 radial velocity, which is
99.8% of sources with a radial velocity in DR2 (7224631). 14800 radial
velocities from DR2 are not propagated to any EDR3 sources because (i)
3871 from the list are found to either not have a DR3 radial velocity
or it differs significantly from its DR2 value, and five high-velocity
stars not on the list are confirmed to have contaminated radial
velocities, in one case because of contamination from the
non-overlapping Radial Velocity Spectrometer windows of a nearby,
bright star; and (ii) 10924 DR2 sources could not be satisfactorily
matched to any EDR3 sources, so their DR2 radial velocities are also
missing from EDR3.
The reliability of radial velocities in EDR3 has improved compared to
DR2 because the update removes a small fraction of erroneous radial
velocities (0.05% of DR2 radial velocities and 5.5% of the list).
Lessons learnt from EDR3 (e.g. bright star contamination) will improve
the radial velocities in future Gaia data releases. The main reason
for radial velocities from DR2 not propagating to EDR3 is not related
to DR2 radial velocity quality. It is because the DR2 astrometry is
based on one component of close binary pairs, while EDR3 astrometry is
based on the other component, which prevents these sources from being
unambiguously matched.
Description:
EDR3 status of high-velocity stars in the negative and positive tail
of DR2's radial velocity distribution.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 43 59 EDR3 status of high-velocity stars in the negative
tail of DR2's radial velocity distribution
tableb2.dat 43 60 EDR3 status of high-velocity stars in the positive
tail of DR2's radial velocity distribution
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
Byte-by-byte Description of file: tableb1.dat tableb2.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaEDR3 Gaia EDR3 source ID
20 A1 --- n_GaiaEDR3 [a] Note (1)
22- 27 F6.1 km/s RV Gaia DR2 radial velocity
29- 32 F4.1 km/s e_RV Gaia DR2 radial velocity error
34- 35 I2 --- Ntrans DR2 number of transits
37- 39 A3 --- EDR3 [Yes/No ] Yes: DR2 RV is in EDR3 or
No: DR2 RV is not in EDR3
41- 43 A3 --- B19 [Yes/No ] Yes: in BOUBERT et al.,
(2019MNRAS.486.2618B 2019MNRAS.486.2618B) list
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Note (1): a: DR2 source ID 1805949089882861696.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 15-Dec-2021