J/A+A/697/A98 Low-mass red giants volume-limited samp. (Benitez-Palacios+, 2025)
Volume-limited sample of low-mass red giant stars, the progenitors of hot
subdwarf stars. II. Sample validation.
Benitez-Palacios D., Uzundag, M., Vuckovic, M., Arancibia-Rojas E.,
Duran-Reyes A., Vos J., Bobrick A., Zorotovic M., Jones M.I.
<Astron. Astrophys. 697, A98 (2025)>
=2025A&A...697A..98B 2025A&A...697A..98B (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, spectroscopic ; Stars, giant ; Radial velocities
Keywords: catalogs - binaries: spectroscopic - stars: late-type -
stars: low-mass - subdwarfs
Abstract:
Binary hot subdwarf B (sdB) stars are typically produced from low-mass
red giant branch (RGB) stars that have lost almost all their envelopes
through binary mass transfer while still fusing helium in their cores.
Particularly, when a low-mass red giant enters stable Roche lobe
overflow (RLOF) mass transfer near the tip of the RGB, a long-period
sdB binary may be formed.
We aim to extend our previous volume-limited sample of 211 stars
within 200pc, a homogeneous sample of low-mass red giants, predicted
progenitors of wide sdB binaries, to 500pc and validate it.
Additionally, our goal is to provide the distribution of stellar
parameters for these stars.
We refined our original 500pc sample by incorporating Gaia DR3
parallax values and interstellar extinction measurements. Next, we
collected multi-epoch high-resolution spectra for 230 stars in the
volume-limited sample using the CORALIE echelle spectrograph from
2019 to 2023. To confirm or discard binarity, we combined astrometric
parameters from Gaia with the resulting radial velocity variations. We
derived the distribution of stellar parameters using evolutionary
models and employed the equivalent evolutionary phase to verify the
evolutionary stage of the stars in our sample. Finally, we compared
our stellar parameters with the literature.
The derived stellar parameters confirmed that 82% of stars in our
sample are indeed in the RGB phase, while 18% are red clump (RC)
contaminants. This was expected due to the overlapping of RGB and RC
stars in the colour-magnitude diagram. Additionally, 75% of the
confirmed RGB stars have a high probability of being part of a binary
system. Comparison with the literature shows good overall agreement
with a scatter ≲15% in stellar parameters, while the masses show
somewhat higher dispersion (∼20%).
We have obtained the most complete volume-limited sample of binary RGB
star candidates within 500 pc. These systems are likely progenitors of
hot subdwarfs and other classes of stripped helium stars.
Description:
We present the continuation of the Uzundag et al.
(2022A&A...668A..89U 2022A&A...668A..89U) 500pc volume- limited sample of low-mass Red
Giants, candidates to be progenitors of long-period hot subdwarf B
stars.
We refined our original 500 pc sample by incorporating Gaia DR3
parallax values and interstellar extinction measurements. Next, we
collected multi- epoch high-resolution spectra for 230 stars in the
volume-limited sample using the CORALIE echelle spectrograph from 2019
to 2023. To confirm or discard binarity, we combined astrometric
parameters from Gaia with the resulting radial velocity variations. We
derived the distribution of stellar parameters using evolutionary
models and employed the Equivalent Evolutionary Phase to verify the
evolutionary stage of the stars in our sample. Finally, we compared
our stellar parameters with the literature.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
tablec1.dat 97 417 Radial velocity measurements
tabled1.dat 151 68 Potential new RGB+MS binaries found in Gaia DR3
NSS catalogue with measured orbital parameters
tabled2.dat 78 162 Potential new RGB+MS binaries found in Gaia DR3
NSS catalogue with no measured orbital parameters
tablee1.dat 221 230 SPECIES results for stars observed with CORALIE
--------------------------------------------------------------------------------
See also:
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
I/357 : Gaia DR3 Part 3. Non-single stars (Gaia Collaboration, 2022)
J/A+A/647/A157 : Stellar parameters of the EXPRESS sample (Soto+, 2021)
Byte-by-byte Description of file: tablec1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Star Star identification from SIMBAD
15- 29 F15.10 deg RAdeg Right Ascension, J2000
31- 44 F14.10 deg DEdeg Declination, J2000
46- 53 F8.2 d JD Julian date (JD-2450000)
55- 56 I2 --- S/N Signal-to-noise ratio
58- 65 F8.3 km/s RV Radial velocity
67- 71 F5.3 km/s e_RV Radial velocity error
73- 80 F8.4 km/s maxdeltaRV ? Maximun radial velocity difference
82- 88 F7.3 --- RUWE ? Renormalized unit wight error (1)
90- 95 F6.3 mas AEN ? Astrometric excess noise (1)
97 I1 --- Category [1/3]? Category (2)
--------------------------------------------------------------------------------
Note (1): Astrometric quality parameter from Gaia DR3
(2023A&A...674A...1G 2023A&A...674A...1G, Cat. I/355)
Note (2): The category is based on the classification method from
Uzundag et al. (2022A&A...668A..89U 2022A&A...668A..89U) as follows:
1 = high probability of being part of a binary system
2 = intermediate probability of being part of a binary system
3 = low probability of being part of a binary system
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tabled1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Star Star identification from SIMBAD
16- 29 F14.10 deg RAdeg Right Ascension, J2000
31- 43 F13.9 deg DEdeg Declination, J2000
45- 50 F6.3 --- RUWE Renormalized unit wight error (1)
52- 56 F5.3 mas AEN Astrometric excess noise (1)
58- 72 A15 --- SolType Solution type (2)
74- 84 F11.7 d Per Orbital period (3)
86- 97 F12.9 d e_Per Orbital period error (3)
99-114 F16.11 d Tp Time of periastron (3)
116-128 F13.8 d e_Tp Time of periastron error (3)
130-137 E8.3 --- ecc Orbital eccentricity (3)
139-151 F13.10 --- e_ecc ? Orbital eccentricity error (3)
--------------------------------------------------------------------------------
Note (1): Astrometric quality parameter from Gaia DR3
(2023A&A...674A...1G 2023A&A...674A...1G, Cat. I/355)
Note (2): Non-single star model adopted:
Orbital = Orbital model for an astrometric binary
AstroSpectroSB1 = Combined astrometric + single lined spectroscopic
orbital model
Note (3): Orbital parameter from Gaia DR3 non-single star catalog
(2023A&A...674A..34G 2023A&A...674A..34G, Cat. I/357)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tabled2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 A14 --- Star Star identification from SIMBAD
16- 29 F14.10 deg RAdeg Right Ascension, J2000
31- 44 F14.10 deg DEdeg Declination, J2000
46- 51 F6.3 --- RUWE Renormalized unit wight error (1)
53- 57 F5.3 mas AEN Astrometric excess noise (1)
59- 78 A20 --- SolType Solution type (2)
--------------------------------------------------------------------------------
Note (1): Astrometric quality parameter from Gaia DR3
(2023A&A...674A...1G 2023A&A...674A...1G, Cat. I/355)
Note (2): Non-single star model adopted as follows:
FirstDegreeTrendSB1 = Single Lined first degree trend
SecondDegreeTrendSB1 = Single Lined second degree trend
Acceleration7 = Acceleration model with 7 parameters
Acceleration9 = Acceleration model with 9 parameters
--------------------------------------------------------------------------------
Byte-by-byte Description of file: tablee1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Star Star identification from SIMBAD
15- 27 F13.9 deg RAdeg Right Ascension, J2000
29- 43 F15.11 deg DEdeg Declination, J2000
45- 46 I2 --- S/N Signal-to-noise ratio
48- 51 I4 K Teff Effective temperature
53- 55 I3 K e_Teff Effective temperature error
57- 61 F5.3 [cm/s2] logg Logarithm of surface gravity
63- 67 F5.3 [cm/s2] e_logg Logarithm of surface gravity error
69- 73 F5.2 [-] [Fe/H] Iron abundance
75- 79 F5.3 [-] e_[Fe/H] Iron abundance error
81- 85 F5.3 km/s Vmic Microturbulent velocity
87- 91 F5.3 km/s e_Vmic Microturbulent velocity error
93- 97 F5.3 km/s Vmac Macroturbulent velocity
99-103 F5.3 km/s e_Vmac Macroturbulent velocity error
105-109 F5.3 km/s vsini Projected rotational velocity
111-115 F5.3 km/s e_vsini Projected rotational velocity error
117-120 F4.2 Msun Mass Stellar mass
122-126 F5.3 Msun E_Mass Stellar mass upper error
128-132 F5.3 Msun e_Mass Stellar mass lower error
134-138 F5.2 Rsun Radius Stellar radius
140-144 F5.3 Rsun E_Radius Stellar radius upper error
146-150 F5.3 Rsun e_Radius Stellar radius lower error
152-156 F5.2 [Lsun] logL Logarithm of stellar luminosity
158-162 F5.3 [Lsun] E_logL Upper error of the logarithm of
stellar luminosity
164-168 F5.3 [Lsun] e_logL Lower error of the logarithm of
stellar luminosity
170-174 F5.2 Gyr Age Stellar age
176-180 F5.3 Gyr E_Age Stellar age upper error
182-186 F5.3 Gyr e_Age Stellar age lower error
188-193 F6.2 --- EEP Equivalent evolutionary phase (1)
195-200 F6.2 --- E_EEP Equivalent evolutionary phase upper error
202-207 F6.2 --- e_EEP Equivalent evolutionary phase lower error
209 I1 --- ProbMS Probability of being on the Main Sequence
211-215 F5.3 --- ProbRGB Probability of being on the Red Gaint Branch
217-221 F5.3 --- ProbHB Probability of being on the Horizontal Branch
--------------------------------------------------------------------------------
Note (1): Indicative of the stellar evolutionary phase from Soto et al.
(2021A&A...647A.157S 2021A&A...647A.157S, Cat. J/A+A/647/A157) as:
1 = Pre-Main Sequence
202 = Zero age Main Sequence
353 = Intermediate age Main Sequence
454 = Terminal age Main Sequence
605 = Tip of the Red Giant Branch
631 = Zero age core helium burning
707 = Terminal age core helium burning
--------------------------------------------------------------------------------
Acknowledgements:
Diego Benitez-Palacios, diego.benitezp(at)postgrado.uv.cl
References:
Uzundag et al., 2022A&A...668A..89U 2022A&A...668A..89U
Volume-limited sample of low-mass red giant stars, the progenitors of hot
subdwarf stars. l. Sample selection and binary classification method
Soto et al., 2021A&A...647A.157S 2021A&A...647A.157S, Cat. J/A+A/647/A157,
SPECIES. II. Stellar parameters of the EXPRESS giant star sample
Gaia DR3, 2023A&A...674A...1G 2023A&A...674A...1G, Cat. I/355,
Gaia Data Release 3. Summary of the content and survey properties
Gaia non-single star, 2023A&A...674A..34G 2023A&A...674A..34G, Cat. I/357,
Gaia Data Release 3. Stellar multiplicity, a teaser for the hidden treasure
(End) Patricia Vannier [CDS] 02-Apr-2025