J/ApJ/953/122 Masses for hot subdwarf stars in LAMOST & Gaia (Lei+, 2023)
Mass distribution for single-lined hot subdwarf stars in LAMOST.
Lei Z., He R., Nemeth P., Zou X., Xiao H., Yang Y., Zhao J.
<Astrophys. J., 953, 122 (2023)>
=2023ApJ...953..122L 2023ApJ...953..122L
ADC_Keywords: Stars, subdwarf; Stars, masses; Stars, diameters;
Energy distributions; Surveys; Optical
Keywords: B subdwarf stars ; Stellar masses ; Spectral energy distribution
Abstract:
Masses for 664 single-lined hot subdwarf stars identified in LAMOST
were calculated by comparing synthetic fluxes from spectral energy
distribution with observed fluxes from a Virtual Observatory service.
Three groups of hot subdwarf stars were selected from the whole sample
according to their parallax precision to study the mass distributions.
We found that He-poor sdB/sdOB stars present a wide mass distribution
from 0.1 to 1.0M☉ with a sharp mass peak at around 0.46M☉,
which is consistent with canonical binary model prediction. He-rich
sdB/sdOB/sdO stars present a much flatter mass distribution than
He-poor sdB/sdOB stars and with a mass peak at around 0.42M☉. By
comparing the observed mass distributions to the predictions of
different formation scenarios, we concluded that the binary merger
channel, including two helium white dwarfs (He-WDs) and He-WD +
main-sequence mergers, cannot be the only main formation channel for
He-rich hot subdwarfs, and other formation channels, such as the
surviving companions from Type Ia supernovae, could also make impacts
on producing this special population, especially for He-rich hot
subdwarfs with masses less than 0.44M☉. He-poor sdO stars also
present a flatter mass distribution with an inconspicuous peak mass at
0.18M☉. The similar mass-ΔRVmax distribution between
He-poor sdB/sdOB and sdO stars supports the scenario that He-poor sdO
stars could be the subsequent evolution stage of He-poor sdB/sdOB
stars.
Description:
In this study, 864 single-lined hot subdwarf stars identified in
Lei+ (2018, J/ApJ/868/70; 2019, J/ApJ/881/135; 2020, J/ApJ/889/117)
were crossmatched with Gaia EDR3 data (see I/350) to obtain their
parallaxes.
We used the VO Sed Analyzer (VOSA; Bayo+ 2008A&A...492..277B 2008A&A...492..277B) of the
Spanish Virtual Observatory (SVO) to search for photometric data for
our sample and convert observed magnitudes to fluxes.
See Section 2.
Table 1 presents the calculated mass values and some useful
information for 664 selected hot subdwarf stars.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 201 664 Main parameters for the 664 hot subdwarfs selected
in this study
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See also:
VI/65 : Evolutionary models of evolved stars (Dorman+ 1993)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
IV/34 : K2 Ecliptic Plane Input Catalog (EPIC) (Huber+, 2017)
I/350 : Gaia EDR3 (Gaia Collaboration, 2020)
I/352 : Distances to 1.47 billion stars in Gaia EDR3 (Bailer-Jones+, 2021)
I/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)
J/ApJ/419/596 : Pop I UV radiation models (Dorman+, 1993)
J/A+A/400/939 : Stellar parameters of 115 HQS sdB stars (Edelmann+, 2003)
J/A+A/430/223 : Parameters of cool companions of sdB stars (Lisker+, 2005)
J/A+A/492/277 : Analysis of Collinder 69 stars with VOSA (Bayo+, 2008)
J/MNRAS/427/2180 : GALEX survey subdwarf atmospheric parameters (Nemeth+, 2012)
J/A+A/551/A31 : New spectral classif. for hot subdwarfs (Drilling+, 2013)
J/A+A/577/A26 : Radial velocities of hot subluminous stars (Geier+, 2015)
J/MNRAS/446/4078 : New white dwarf stars in SDSS DR10 (Kepler+, 2015)
J/A+A/595/A35 : Low-mass helium WDs evolutionary models (Istrate+, 2016)
J/MNRAS/455/3413 : White dwarf & subdwarf stars in SDSS DR12 (Kepler+, 2016)
J/ApJ/818/202 : Hot subdwarf stars in LAMOST DR1 (Luo+, 2016)
J/A+A/600/A50 : Catalog of hot subdwarf stars (Geier+, 2017)
J/ApJ/868/70 : Hot subdwarf stars from Gaia DR2 and LAMOST DR5 (Lei+, 2018)
J/MNRAS/486/2169 : White dwarf and subdwarf stars in SDSS DR14 (Kepler+, 2019)
J/ApJ/881/135 : Hot subdwarf stars from Gaia DR2 & LAMOST. II. (Lei+, 2019)
J/ApJ/881/7 : Hot subdwarf stars from LAMOST DR5 & Gaia DR2 (Luo+, 2019)
J/A+A/635/A193 : Catalogue of hot subdwarf stars DR2 (Geier, 2020)
J/ApJ/889/117 : Hot subdwarf stars from Gaia & LAMOST DR6+7. I. (Lei+, 2020)
J/A+A/642/A180 : Hot subdwarf stars binarity (Pelisoli+, 2020)
J/A+A/650/A102 : SDSS J160429.12+100002.2 spectra (Irrgang+, 2021)
J/ApJS/256/28 : Hot subdwarf stars with Gaia DR2 & LAMOST DR7 (Luo+, 2021)
J/ApJ/933/94 : ELM survey. IX. Low-mass SDSS+Gaia WD bin. (Brown+, 2022)
J/A+A/662/A40 : Hot subdwarf stars studied with Gaia (Culpan+, 2022)
J/A+A/661/A113 : Hot subdwarf stars Radial velocity variab. (Geier+, 2022)
J/A+A/658/A22 : Kinematic properties of white dwarfs (Raddi+, 2022)
J/ApJ/942/109 : Hot subdwarf stars from LAMOST DR8 (Lei+, 2023)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg LAMOST Right Ascension (J2000)
13- 22 F10.7 deg DEdeg [-7/82] LAMOST Declination (J2000)
24- 32 I9 --- obsID [1203114/746415156] LAMOST observation
identifier
34- 52 I19 --- Gaia Gaia EDR3 observation identifier
54- 62 F9.6 mag Gmag [10.46/17.67] Gaia EDR3 G-band magnitude
64- 71 F8.6 mag e_Gmag [0.0027/0.007] Uncertainty in Gmag
73- 78 F6.4 mas plx [0.27/7.1] Parallax, Gaia EDR3, after
zeropoint correction
80- 85 F6.4 mas e_plx [0.02/0.2] Uncertainty in plx
87- 91 I5 K Teff [21290/84550] Surface effective temperature
from Lei et al. (2018, 2019b, 2020) (1)
93- 97 I5 K e_Teff [565/14690] Uncertainty in Teff
99- 102 F4.2 [cm/s2] logg [5/7] Log of surface gravity
from Lei et al. (2018, 2019b, 2020) (1)
104- 107 F4.2 [cm/s2] e_logg [0.05/0.6] Uncertainty in logg
109- 115 A7 --- spclass Subdwarf classification
from Lei et al. (2018, 2019b, 2020) (1) (2)
117- 121 F5.3 mag E(B-V) [0.007/0.96] Reddening
123- 127 F5.3 mag e_E(B-V) [0/0.061] Uncertainty in E (B-V)
129- 135 F7.3 [rad] AngD [-11.76/-10.3] Median Angular diameter,
log(radians)
137- 141 F5.3 [rad] E_AngD [0.002/0.3] Upper uncertainty in AngD (3)
143- 147 F5.3 [rad] e_AngD [0.003/0.2] Lower uncertainty in AngD (3)
149- 153 F5.3 Rsun Rstar [0.052/0.5] Median Radius
155- 159 F5.3 Rsun E_Rstar [0.001/0.1] Upper uncertainty in Rstar (3)
161- 165 F5.3 Rsun e_Rstar [0.001/0.06] Lower uncertainty in Rstar (3)
167- 172 F6.1 Lsun Lstar [3.9/2549] Median Luminosity
174- 179 F6.1 Lsun E_Lstar [0.5/2480] Upper uncertainty in Lstar (3)
181- 186 F6.1 Lsun e_Lstar [0.4/1266] Lower uncertainty in Lstar (3)
188- 191 F4.2 Msun Mstar [0.11/1] Median Mass
193- 196 F4.2 Msun E_Mstar [0.02/2.61] Upper uncertainty in Mstar (3)
198- 201 F4.2 Msun e_Mstar [0.02/0.7] Lower uncertainty in Mstar (3)
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Note (1): Lei+ (2018, J/ApJ/868/70; 2019, J/ApJ/881/135; 2020, J/ApJ/889/117)
Note (2): Subdwarf classifications as follows:
He-sdB = Helium-rich, sdB (6 occurrences)
He-sdO = Helium-rich, sdO (14 occurrences)
He-sdOB = Helium-rich, sdOB (90 occurrences)
sdB = B-type subdwarf (350 occurrences)
sdO = O-type subdwarf (71 occurrences)
sdOB = OB-intermediate subdwarf (133 occurrences)
Note (3): The Upper uncertainty is the difference of the 84th and Median
percentile values; the Lower uncertainty is the difference of the 16th
and the Median percentile values.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 24-Sep-2025