J/A+A/685/A134 Blue Horizontal Branch stars catalog (Culpan+, 2024)
Probing the inner Galactic halo with blue horizontal-branch stars.
Gaia DR3-based catalogue with atmospheric and stellar parameters.
Culpan R., Pelisoli I., Geier S., Pelisoli I., Heber U., Kubatova B.,
Cabezas M.
<Astron. Astrophys. 685, A134 (2024)>
=2024A&A...685A.134C 2024A&A...685A.134C (SIMBAD/NED BibCode)
ADC_Keywords: Blue objects ; Parallaxes, trigonometric ;
Stars, horizontal branch ; Stars, halo
Keywords: catalogs - Hertzsprung-Russell and C-M diagrams -
stars: horizontal-branch
Abstract:
Stars that are found on the blue horizontal-branch (BHB) evolved from
low-mass stars that have completed their core hydrogen-burning main
sequence (MS) stage and undergone the helium flash at the end of their
red giant phase. Hence, they are very old objects that can be used as
markers in studying galactic structure and formation history. The fact
that their luminosity is virtually constant at all effective
temperatures also makes them good standard candles.
We have compiled a catalogue of BHB stars with stellar parameters
calculated from spectral energy distributions (SEDs) constructed using
data from multiple large-scale photometric surveys. In addition, we
update our previous Gaia Early Data Release 3 (EDR3) catalogue of BHB
stars with parallax errors less than 20% by using the SED results to
define the selection criteria. The purpose of these catalogues is to
create a set of BHB star candidates with reliable stellar parameters.
In addition, they provide a more complete full-sky catalogue with
candidate objects found along the whole BHB from where RR-Lyrae are
found on the instability strip to the extreme horizontal-branch (EHB).
We selected a large dataset of Gaia Data Release 3 (DR3) objects based
only on their position on the colour-magnitude diagram (CMD), along
with the tangential velocity and parallax errors. The SEDs were then
used to evaluate contamination levels in the dataset and derive
optimised data quality acceptance constraints. This allowed us to
extend the Gaia DR3 colour and absolute magnitude criteria further
towards the EHB. The level of contamination found using SED analysis
was confirmed by acquiring spectra using the Ondrejov Echelle
spectrograph, attached to the Perek 2m telescope at the Astronomical
Institute of the Czech Academy of Sciences.
We present a catalogue of 9172 Galactic halo BHB candidate stars with
atmospheric and stellar parameters calculated from synthetic SEDs. We
also present an extended Gaia DR3-based catalogue of 22335 BHB
candidate stars with a wider range of effective temperatures and Gaia
DR3 parallax errors of less than 20%. This represents an increase of
33% compared to the our 2021 catalogue with a contamination level of
10%.
Description:
The paper describes the motivation, procedure, and justification to
reproduce the tables below.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablea1.dat 998 22335 Catalogue of BHB
--------------------------------------------------------------------------------
See also:
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
Byte-by-byte Description of file: tablea1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 I19 --- GaiaEDR3 Gaia EDR3 source identifier
21- 42 F22.18 deg RAdeg Gaia EDR3 right ascension (ICRS)
at Ep=2016.0
44- 64 E21.15 deg DEdeg Gaia EDR3 declination (ICRS) at Ep=2016.0
66- 87 F22.18 deg GLON Galaclic longitude
89-110 F22.18 deg GLAT Galaclic latitude
112-130 F19.17 mas plx Gaia parallax
132-151 F20.18 mas e_plx Gaia parallax error
153-174 E22.16 mag GMAG Absolute magnitude in G-band
176-197 E22.16 mag GMAGzpc Absolute magnitude in G-band
from zpc parallax
199-217 F19.16 mag Gmag Gaia apparent G magnitude
219-240 E22.16 mag BP-RP Gaia GBP-GRP colour index
242-263 E22.16 mag E(BP/RP) Corrected BP/RP excess factor
265-285 F21.19 mag e_E(BP/RP) Corrected BP/RP excess factor error
287-307 E21.15 mas/yr pmRA Gaia proper motion along RA, pmRA*cosDE
309-329 F21.19 mas/yr e_pmRA Gaia proper motion along RA error
331-354 F24.19 mas/yr pmDE Gaia proper motion along DE
356-376 F21.19 mas/yr e_pmDE Gaia proper motion along DE error
378-397 F20.16 mas/yr pm Gaia total proper motion
399-418 F20.18 mas/yr e_pm Gaia total proper motion error
420-437 F18.14 km/s vt Tangential velocity
439-458 F20.16 km/s e_vt Tangential velocity error
460-480 E21.16 --- EFluxErr ? Excess flux error
482-490 E9.2 mas zp Parallax zero point
492-501 F10.8 mas plxzpc Zero-point-corrected parallax
503 I1 --- Ws5 Gaia objects within 5 arcsec of
BHB candidate
505-524 E20.15 ct FG5s Total G flux from within 5 arcsec radius
of BHB candidate
526-536 F11.9 --- cff Fraction of 5 arcsec flux that comes
from BHB candidate
538-542 A5 --- SEDFlag Flag for SED calculation
544-562 F19.15 --- SEDlogtheta ? Angular diameter log(theta)
564-584 E21.16 mag SEDe44m55 ? Reddening
586-604 F19.13 K SEDTeff ? Effective temperature
606-623 F18.16 [cm/s2] SEDlogg ? Surface gravity
625-647 E23.16 --- SEDz ? Metallicity
649-666 F18.16 Rsun SEDR ? Median stellar radius from
SED calculation
668-685 F18.16 Msun SEDM ? Median stellar mass from SED calculation
687-704 F18.15 Lsun SEDL ? Median stellar luminosity from
SED calculation
706-725 F20.18 Rsun E_SEDR ? Stellar radius minus error from
SED calculation
727-746 F20.18 Msun E_SEDM ? Stellar mass plus error from
SED calculation
748-766 F19.16 Lsun E_SEDL ? Stellar luminosity plus error from
SED calculation
768-786 F19.16 Lsun e_SEDL ? Stellar luminosity minus error from
SED calculation
788-807 F20.18 Msun e_SEDM ? Stellar mass minus error from
SED calculation
809-828 F20.18 Rsun e_SEDR ? Stellar radius plus error from
SED calculation
830-850 E21.15 --- e_SEDlogtheta ? Surface gravity minus error
852-872 E21.16 mag e_SEDe44m55 ? Reddening minus error
874-893 F20.15 K e_SEDTeff ? Effective temperature minus error
895-913 F19.17 [cm/s2] e_SEDlogg ? Surface gravity minus error
915-933 F19.17 [cm/s2] E_SEDlogg ? Surface gravity plus error
935-954 F20.15 K E_SEDTeff ? Effective temperature plus error
956-976 E21.16 mag E_SEDe44m55 ? Reddening plus error
978-998 E21.15 --- E_SEDlogtheta ? Angular diameter plus error
--------------------------------------------------------------------------------
Acknowledgements:
Richard Culpan, rick(at)culpan.de
(End) Patricia Vannier [CDS] 19-Mar-2024