J/ApJ/937/110 B-type stars abundances from LAMOST DR5 LRS sp. (Liu+, 2022)
Chemical composition of B-type stars from LAMOST DR5.
Liu Z., Cui W., Liu C., Alexeeva S., Shi J., Zhao G.
<Astrophys. J., 937, 110 (2022)>
=2022ApJ...937..110L 2022ApJ...937..110L
ADC_Keywords: Abundances; Stars, B-type; Spectra, optical; Spectral types;
Rotational velocities; Stars, giant; Effective temperatures
Keywords: Early-type stars ; Stellar atmospheres ; Stellar rotation ;
Chemical abundances
Abstract:
We present detailed criteria for the classification of subtypes of
B-type supergiants and apply them to 97 supergiants chosen manually
from the LAMOST DR5 data set. We obtained the physical parameters
(effective temperature, surface gravity, projected rotational
velocity) and chemical abundances of C and Si for 103 B-type stars,
including 62 supergiants. Non-LTE TLUSTY atmospheric models are
employed in our analysis. Projected rotational velocities of B-type
stars are found to be systematically smaller than those of the old
clusters in the Milky Way. The spectral types and luminosity classes
of our manually classified B-type stars are consistent with their
effective temperatures and surface gravities derived from the model
spectral matching method, respectively. The obtained C and Si
abundances for most of our B-type stars are subsolar. Our results
indicate that a silicon abundance gradient is -0.0419±0.0226dex/kpc
in the region of 7.1kpc≤Rg≤14.1kpc, which is in agreement with
previous studies.
Description:
The Large sky Area Multi-Object Spectroscopic Telescope (LAMOST) is a
4m reflected Schmidt telescope with a wavelength coverage of
3690-9100Å and low resolution R∼1800. LAMOST DR5 includes its pilot
survey, 5yr of LAMOST regular survey data, and contains more than
9 million low-resolution spectra.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 119 138 The stellar parameters and elemental abundances
for B-type stars in LAMOST; updated version
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See also:
III/195 : Atlas of Optical Spectral Classification OB Stars (Walborn+ 1990)
III/274 : Galactic O-Star Spectroscopic Survey (GOSSS) (Sota+, 2014)
V/164 : LAMOST DR5 catalogs (Luo+, 2019)
V/156 : LAMOST DR7 catalogs (Luo+, 2019)
J/A+A/434/1125 : B-type Supergiants in the SMC (Dufton+, 2005)
J/A+A/436/687 : SMC NGC 346-11 and AV 304 spectra (Hunter+, 2005)
J/AJ/129/809 : B-star rot. velocities in h and χ Persei (Strom+, 2005)
J/A+A/457/265 : The VLT-FLAMES Survey of Massive Stars (Dufton+, 2006)
J/A+A/466/277 : VLT-FLAMES survey of massive stars (Hunter+, 2007)
J/A+A/471/625 : VLT-FLAMES survey of massive stars (Trundle+, 2007)
J/AJ/133/1092 : vsini of B0-B3 stars in 7 young clusters (Wolff+, 2007)
J/A+A/539/A143 : Nearby B-stars stellar param. and abundances (Nieva+, 2012)
J/A+A/562/A135 : Northern Galactic OB stars vsini (Simon-Diaz+, 2014)
J/A+A/580/A17 : α-element abundances of Cepheid stars (Genovali+, 2015)
J/A+A/603/A91 : VLTS. B-type main-sequence binary systems (Garland+, 2017)
J/A+A/613/A65 : Spectroscopic parameters of O-type stars (Holgado+, 2018)
J/AJ/156/171 : Cepheid abundances: spatial gradients (Luck, 2018)
J/AJ/158/73 : OB stars & their bow shock nebulae (Kobulnicky+, 2019)
J/ApJS/241/32 : OB stars from the LAMOST DR5 spectra (Liu+, 2019)
J/ApJS/253/22 : Ks absolute magnitudes from LAMOST for OB stars (Xiang+, 2021)
http://dr5.lamost.org/v3/ : LAMOST DR5 v3 homepage
http://dr6.lamost.org/ : LAMOST DR6 v2 online access
http://dr7.lamost.org/v2.0/ : LAMOST DR7 v2.0 online
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 9 I9 --- ObsID [5116047/647602217] LAMOST Observation ID (1)
11- 29 A19 --- LAMOST LAMOST identifier (JHHMMSS.ss+DDMMSS.s)
31- 39 F9.5 deg RAdeg [13.98/346.14] Right ascension (J2000)
41- 48 F8.5 deg DEdeg [-3.04/58.7] Declination (J2000)
50- 55 F6.2 --- S/N [16/974] Signal-to-noise ratio at the g-band
57- 66 A10 --- SpT Spectral type using our criteria
68- 69 I2 kK Teff [15/30]? Effective temperature
71 A1 --- f_Teff Flag on Teff (2)
73- 76 F4.2 [cm/s2] logg [2.25/4]? Log of surface gravity
78- 80 I3 km/s vsini [10/270]? Rotational velocity
82- 83 A2 --- n_vsini The metal line used to obtain vsini
85- 86 I2 km/s Vt [5/20]? Microturbulent velocity
88- 91 F4.2 [-] logeC [6.93/8.3]? C abundance
93- 96 F4.2 [-] e_logeC [0.05/0.5]? logeC uncertainty
98- 101 F4.2 [-] logeSi [6.54/8.13]? Si abundance
103- 106 F4.2 [-] e_logeSi [0/0.5]? logeSi uncertainty
108- 113 F6.3 kpc Rg [3.7/19.3]? Galactocentric distance (3)
115- 119 F5.3 kpc e_Rg [0/3]? Rg uncertainty
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Note (1): Note that obsID 647602217 (Target=J061054.29+082614.4) has been
discarded in DR5 due to an update to the LAMOST website and is not
included in Cat. V/164 but can be found in LAMOST DR6 online
and in the DR7 catalog (V/156).
Note (2): Teff estimated using:
c = Case1 (χ2HHeHe)
d = Case2 (χ2HHeCMg)
e = its spectral type
Note (3): the Galactocentric distance of Xiang+ (2021, J/ApJS/253/22), and we
only calculate to three decimal places for the error of Rg.
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Acknowledgements:
Zhicun LIU [liuzhicun at hebtu.edu.cn]
History:
From electronic version of the journal
* 09-Sep-2024: Insert into VizieR
* 09-Sep-2024: 13 LAMOST target identifiers corrected by the author
(rows 36-39 and 46-54):
J061054.29+082614.4, J061118.08+213339.9, J060832.10+213639.2,
J060832.12+213639.3, J061846.63+230920.4, J061956.83+234421.3,
J062003.07+241346.1, J063341.95+024146.8, J061754.58+222431.0,
J063457.00+024538.3, J063745.01+004509.3, J061825.41+233415.3,
J063456.90+024549.6 (with ObsID=428016106) were mixed-up.
(End) Emmanuelle Perret [CDS] 12-Aug-2024