J/ApJ/894/5 APOGEE2-N NIR spectra of B-type stars (Ramirez-Preciado+, 2020)
Spectral classification of B stars: the empirical sequence using SDSS-IV/APOGEE
Near-IR data.
Ramirez-Preciado V.G., Roman-Lopes A., Roman-Zuniga C.G., Hernandez J.,
Garcia-Hernandez D.A., Stassun K., Stringfellow G.S., Kim J.S.
<Astrophys. J., 894, 5-5 (2020)>
=2020ApJ...894....5R 2020ApJ...894....5R (SIMBAD/NED BibCode)
ADC_Keywords: Stars, B-type; Spectra, infrared; Optical; Equivalent widths;
Spectral types
Keywords: B stars; Spectroscopy; Infrared astronomy; Optical identification
Abstract:
We present a semi-empirical spectral classification scheme for normal
B-type stars using near-infrared (NIR) spectra (1.5-1.7µm) from
the Sloan Digital Sky Survey Apache Point Observatory Galaxy Evolution
Experiment (APOGEE2)-N data release 14 (DR14) database. The main
motivation for working with B-type stars is their importance in the
evolution of young stellar clusters; however, we also take advantage
of having a numerous sample (316 stars) of B-type star candidates in
APOGEE2-N, for which we also have optical (3600-9100Å)
counterparts from the Large Sky Area Multi-Object Fiber Spectroscopic
Telescope (LAMOST) survey. By first obtaining an accurate spectral
classification of the sources using the LAMOST DR3 spectra and the
canonical spectral classification scheme, we found a linear relation
between optical spectral types and the equivalent widths of the
hydrogen lines of the Brackett series in the APOGEE2-N NIR spectra.
This relation extends smoothly from a similar relation for O and early
B stars found by Roman-Lopes+ (2018, J/ApJ/855/68). This way, we
obtain a catalog of B-type sources with features in both the optical
and NIR and a classification scheme refined down to one spectral
subclass.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 112 315 NIR parameters for the control sample in APOGEE-2
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See also:
III/274 : Galactic O-Star Spectroscopic Survey (GOSSS) (Sota+, 2014)
V/153 : LAMOST DR4 catalogs (Luo+, 2018)
III/284 : APOGEE-2 data from DR16 (Johnsson+, 2020)
J/ApJS/107/281 : Atlas of hot, luminous stars at 2 microns (Hanson+ 1996)
J/ApJS/161/154 : Near-IR spectral atlas of OB stars (Hanson+, 2005)
J/ApJ/661/1119 : Spectroscopy in the 25 Ori group (Briceno+, 2007)
J/AN/331/349 : O, B-type & red supergiant masses & lum. (Hohle+, 2010)
J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)
J/ApJ/855/68 : Massive stars in SDSS-IV/APOGEE SURVEY. I. (Roman-Lopes+, 2018)
J/ApJS/241/32 : OB stars from the LAMOST DR5 spectra (Liu+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 18 A18 --- ID APOGEE identifier (2MHHMMSSss+DDMMSSs)
20- 21 I2 h RAh Hour of Right Ascension (J2000)
23- 24 I2 min RAm Minute of Right Ascension (J2000)
26- 30 F5.2 s RAs Second of Right Ascension (J2000)
32- 32 A1 --- DE- Sign of the Declination (J2000)
33- 34 I2 deg DEd Degree of Declination (J2000)
36- 37 I2 arcmin DEm Arcminute of Declination (J2000)
39- 42 F4.1 arcsec DEs Arcsecond of Declination (J2000)
44- 49 F6.3 0.1nm Br11 [2.75/10.95] Equivalent width, HI 11-4
(Brackett 1681.1111nm)
51- 57 F7.5 0.1nm e_Br11 [0/2.21] Uncertainty in Br11
59- 63 F5.2 0.1nm FWHMBr11 [15.65/65.82] Full width at half maximum,
HI 11-4
65- 72 F8.5 0.1nm e_FWHMBr11 [0/25] Uncertainty in FWHMBr11
74- 79 F6.3 0.1nm Br13 [1.83/11.41] Equivalent width, HI 13-4
(Brackett 1611.3714nm)
81- 87 F7.5 0.1nm e_Br13 [0.08/1.3] Uncertainty in Br13
89- 94 F6.3 0.1nm FWHMBr13 [16.5/86.1] Full width at half maximum,
HI 13-4
96-103 F8.5 0.1nm e_FWHMBr13 [0/32] Uncertainty in FWHMBr13
105-112 A8 --- SpT Spectral type
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 09-Sep-2021