J/AJ/152/31 Spectral classification of O Vz stars from GOSSS (Arias+, 2016)
Spectral classification and properties of the OVz stars in the galactic O star
spectroscopic survey (GOSSS).
Arias J.I., Walborn N.R., Diaz S.S., Barba R.H., Apellaniz J.M.,
Sabin-Sanjulian C., Gamen R.C., Morrell N.I., Sota A., Marco A.,
Negueruela I., Leao J.R.S., Herrero A., Alfaro E.J.
<Astron. J., 152, 31-31 (2016)>
=2016AJ....152...31A 2016AJ....152...31A (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, O ; MK spectral classification ;
Spectral types ; Equivalent widths ; Redshifts
Keywords: stars: early-type - stars: fundamental parameters - surveys
Abstract:
On the basis of the Galactic O Star Spectroscopic Survey (GOSSS), we
present a detailed systematic investigation of the O Vz stars. The
currently used spectral classification criteria are rediscussed, and
the Vz phenomenon is recalibrated through the addition of a
quantitative criterion based on the equivalent widths of the
HeIλ4471, HeIIλ4542, and HeIIλ4686 spectral
lines. The GOSSS O Vz and O V populations resulting from the newly
adopted spectral classification criteria are comparatively analyzed.
The locations of the O Vz stars are probed, showing a concentration of
the most extreme cases toward the youngest star-forming regions. The
occurrence of the Vz spectral peculiarity in a solar-metallicity
environment, as predicted by the FASTWIND code, is also investigated,
confirming the importance of taking into account several processes for
the correct interpretation of the phenomenon.
Description:
All of the observations used in this work come from the Galactic O
Star Spectroscopic Survey (GOSSS). Details on the data and analysis
procedures are fully discussed in the three papers from the project
(Sota et al. 2011, 2014, Cat. III/274; Maiz Apellaniz et al.
2016ApJS..224....4M 2016ApJS..224....4M).
GOSSS is a long-term systematic survey of all of the Galactic stars
ever classified as O. This project provides moderate resolution
(R∼2500) spectroscopy in the blue-violet region (approximately
3900-5000Å) with a high signal-to-noise ratio, typically
S/N∼200-300. The spectral types are available through the latest
version of the Galactic O Star Catalog (GOSC; Maiz Apellaniz et al.
2004, Cat. V/116). In this paper, we include 226 O stars from both
hemispheres pertaining to the three published GOSSS installments.
The categories and numbers that characterize our sample objects are
the following: (1) objects that are single lined in the GOSSS spectra
and for which no evidence of binarity is known (132 stars listed in
Table1); (2) objects that are single lined in the GOSSS spectra but
are known to be spectroscopic binaries (SBs) from high-resolution data
(45 binaries, Table2); (3) objects that are double lined in the GOSSS
spectra (explicit SB2) for which the line separation is sufficiently
large to allow measurements of the CDs and EWs of the individual
components by the use of deblending methods (23 binaries providing 32
components with spectral types earlier than O9); and (4) explicit SB2
whose spectral components are not sufficiently separated to be
measured individually (15 binaries). Binaries belonging to groups (3)
and (4) are listed in Table3.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 89 132 *O V stars in GOSSS with no evidence of binarity
table2.dat 89 45 *O binaries with single-lined profiles at the
GOSSS resolution
table3.dat 118 38 *Double-lined binary Stars in GOSSS
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Note on table1.dat table2.dat table3.dat: GOSSS = Galactic O Star Spectroscopic
Survey (see Sota et al. 2014, Cat. III/274).
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See also:
III/274 : Galactic O-Star Spectroscopic Survey (Sota+, 2014)
V/116 : Galactic O star catalog (Maiz-apellaniz+, 2004)
J/A+A/564/A39 : VLTS. OVz stars in 30 Dor (Sabin-Sanjulian+, 2014)
Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Object name
25- 26 I2 h RAh Hour of Right Ascension (J2000)
28- 29 I2 min RAm Minute of Right Ascension (J2000)
31- 35 F5.2 s RAs Second of Right Ascension (J2000)
37 A1 --- DE- Sign of the Declination (J2000)
38- 39 I2 deg DEd Degree of Declination (J2000)
41- 42 I2 arcmin DEm Arcminute of Declination (J2000)
44- 47 F4.1 arcsec DEs Arcsecond of Declination (J2000)
49- 64 A16 --- SpT Spectral type
66- 69 A4 --- Ref Reference (G1)
71- 74 F4.2 0.1nm W4471 [0/1.1]? Equivalent width of HeI 4471 (in Å)
76- 79 F4.2 0.1nm W4542 [0.4/1.2]? Equivalent width of HeII 4542 (in Å)
81- 84 F4.2 0.1nm W4686 [0.4/1.3]? Equivalent width of HeII 4686 (in Å)
86- 89 F4.2 --- Z [0.7/1.5]? Metallicity (G2)
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Name Object name
25- 26 I2 h RAh Hour of Right Ascension (J2000)
28- 29 I2 min RAm Minute of Right Ascension (J2000)
31- 35 F5.2 s RAs Second of Right Ascension (J2000)
37 A1 --- DE- Sign of the Declination (J2000)
38- 39 I2 deg DEd Degree of Declination (J2000)
41- 42 I2 arcmin DEm Arcminute of Declination (J2000)
44- 47 F4.1 arcsec DEs Arcsecond of Declination (J2000)
49- 73 A25 --- SpT Spectral type
75- 78 A4 --- Ref Reference (G1)
80- 83 F4.2 0.1nm W4471a [0.11/0.66]? Equivalent width of HeI 4471 for
primary (in Å)
85- 88 F4.2 0.1nm W4471b [0.07/0.42]? Equivalent width of HeI 4471 for
secondary (in Å)
90- 93 F4.2 0.1nm W4542a [0.27/0.78]? Equivalent width of HeII 4542 for
primary (in Å)
95- 98 F4.2 0.1nm W4542b [0.27/0.45]? Equivalent width of HeII 4542 for
secondary (in Å)
100-103 F4.2 0.1nm W4686a [0.34/0.85]? Equivalent width of HeII 4686 for
primary (in Å)
105-108 F4.2 0.1nm W4686b [0.27/0.38]? Equivalent width of HeII 4686 for
secondary (in Å)
110-113 F4.2 --- Za [0.65/1.26]? Primary metallicity (G2)
115-118 F4.2 --- Zb [0.75/1.14]? Secondary metallicity (G2)
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Global Notes:
Note (G1): References are denoted with the codes:
MA16 = Maiz-apellaniz et al. 2016ApJS..224....4M 2016ApJS..224....4M;
S11 = Sota et al. 2011 (Cat. III/274);
S11a = Simon-Diaz et al. 2011IAUS..272..310S 2011IAUS..272..310S;
S14 = Sota et al. 2014 (Cat. III/274).
Note (G2):
Computed from Equation (1) in Section 4.2:
Z=[EW(HE II λ4686]/Max[EW(He I λ4471),EW(He II λ4542)],
(see Sota et al. 2014ApJS..211...10S 2014ApJS..211...10S,).
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History:
From electronic version of the journal
(End) Sylvain Guehenneux [CDS] 19-Oct-2016