J/MNRAS/523/4049 CEMP in Gaia DR3 (Lucey+, 2023)
Carbon-Enhanced Metal-Poor star candidates from BP/RP Spectra in Gaia DR3.
Lucey M., Al Kharusi N., Hawkins K., Ting Y.-S., Ramachandra N.,
Price-Whelan A.M., Beers T.C., Sun Lee Y., Yoon J.
<Mon. Not. R. Astron. Soc. 523, 4049 (2023)>
=2023MNRAS.523.4049L 2023MNRAS.523.4049L (SIMBAD/NED BibCode)
ADC_Keywords: Stars, carbon ; Optical
Keywords: stars: abundances - stars: carbon - stars: Population II -
Galaxy: abundances
Abstract:
Carbon-enhanced metal-poor (CEMP) stars comprise almost a third of
stars with [Fe/H]←2, although their origins are still poorly
understood. It is highly likely that one sub-class (CEMP-s stars) is
tied to mass-transfer events in binary stars, while another sub-class
(CEMP-no stars) are enriched by the nucleosynthetic yields of the
first generations of stars. Previous studies of CEMP stars have
primarily concentrated on the Galactic halo, but more recently they
have also been detected in the thick disc and bulge components of the
Milky Way. Gaia DR3 has provided an unprecedented sample of over 200
million low-resolution (R∼50) spectra from the BP and RP
photometers. Training on the CEMP catalogue from the SDSS/SEGUE
database, we use XGBoost to identify the largest all-sky sample of
CEMP candidate stars to date. In total, we find 58872 CEMP star
candidates, with an estimated contamination rate of 12 per cent. When
comparing to literature high-resolution catalogues, we positively
identify 60-68 per cent of the CEMP stars in the data, validating our
results and indicating a high completeness rate. Our final catalogue
of CEMP candidates spans from the inner to outer Milky Way, with
distances as close as r∼0.8kpc from the Galactic centre, and as far
as r>30kpc. Future higher resolution spectroscopic follow-up of
these candidates will provide validations of their classification and
enable investigations of the frequency of CEMP-s and CEMP-no stars
throughout the Galaxy, to further constrain the nature of their
progenitors.
Description:
For 182815672 stars with XP spectra that were released in Gaia DR3,
we present the derived probability that the star is enhanced in carbon
([C/Fe]>+0.7).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cemp.dat 28 58872 CEMP candidates (P≥0.5)
catalog.dat 28 182815672 Probabilities of each star being Carbon-Enhanced
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See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: cemp.dat catalog.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR3 Gaia DR3 source ID
21- 28 F8.6 --- Cpred Probability of being Carbon-Enhanced
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Acknowledgements:
Madeline Lucey, m_lucey(at)utexas.edu
(End) Madeline Lucey [UT Austin], Patricia Vannier [CDS] 26-Jun-2023