J/A+A/601/A79 VLTS. Properties of O dwarf in 30 Dor (Sabin-Sanjulian+, 2017)
The VLT-FLAMES Tarantula Survey.
XXVI: Properties of the O-dwarf population in 30 Doradus.
Sabin-Sanjulian C., Simon-Diaz S., Herrero A., Puls J., Schneider F.R.N.,
Evans C.J., Garcia M., Najarro F., Brott I., Castro N., Crowther P.A.,
de Koter A., de Mink S.E., Grafener G., Grin N.J., Holgado G., Langer N.,
Lennon D.J., Maiz Apellaniz J., Ramirez-Agudelo O.H., Sana H., Taylor W.D.,
Vink J.S., Walborn N.R.
<Astron. Astrophys. 601, A79 (2017)>
=2017A&A...601A..79S 2017A&A...601A..79S (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Stars, O ; Stars, dwarfs ;
Rotational velocities ; Effective temperatures
Keywords: Magellanic Clouds - stars: atmospheres - stars: early-type -
stars: fundamental parameters - stars: massive
Abstract:
The VLT-FLAMES Tarantula Survey has observed hundreds of O-type stars
in the 30 Doradus region of the Large Magellanic Cloud (LMC). We study
the properties of 105 apparently single O-type dwarfs. To determine
stellar and wind parameters, we used the IACOB-GBAT package, an
automatic procedure based on a large grid of atmospheric models
calculated with the FASTWIND code. In addition to classical
techniques, we applied the Bayesian BONNSAI tool to estimate
evolutionary masses. We provide a new calibration of effective
temperature vs. spectral type for O-type dwarfs in the LMC, based on
our homogeneous analysis of the largest sample of such objects to date
and including all spectral subtypes. Good agreement with previous
results is found, although the sampling at the earliest subtypes could
be improved. Rotation rates and helium abundances are studied in an
evolutionary context. We find that most of the rapid rotators (vsini
higher than 300km/s) in our sample have masses below 25 MSun and
intermediate rotation-corrected gravities (loggc between 3.9 and
4.1). Such rapid rotators are scarce at higher gravities (i.e. younger
ages) and absent at lower gravities (larger ages). This is not
expected from theoretical evolutionary models, and does not appear to
be due to a selection bias in our sample. We compare the estimated
evolutionary and spectroscopic masses, finding a trend that the former
is higher for masses below 20M☉. This can be explained as a
consequence of limiting our sample to the O-type stars, and we see no
compelling evidence for a systematic mass discrepancy. For most of the
stars in the sample we were unable to estimate the wind-strength
parameter (hence mass-loss rates) reliably, particularly for objects
with luminosity lower than logL/L☉ about 5.1. Ultraviolet
spectroscopy is needed to undertake a detailed investigation of the
wind properties of these dwarfs.
Description:
Results from the quantitative spectroscopic analysis of 105 O-type
dwarfs belonging to the 30 Doradus region in the LMC are presented.
Stellar and wind parameters, as well as stellar radii, luminosities
and masses are given.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 88 85 Stellar and wind parameters for stars analyzed
with HHe diagnostics
tablea2.dat 64 20 *First estimates of stellar and wind parameters
for stars analyzed with HHeN diagnostics
tableb1.dat 107 85 Radii, luminosities and masses for stars
analyzed with HHe diagnostics
tableb2.dat 84 20 First estimates of radii, luminosities and
masses for stars analyzed with HHeN diagnostics
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Note on tablea2.dat: Y(He) was fixed to 0.10±0.02.
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See also:
J/A+A/530/A108 : VLT-FLAMES Tarantula Survey (Evans+, 2011)
J/A+A/550/A107 : VLTS. RV catalogue of O stars in 30 Doradus (Sana+, 2013)
J/A+A/550/A108 : DIB in VLT-FLAMES Tarantula Survey (van Loon+, 2013)
J/A+A/550/A109 : VLTS: vsini measures (Dufton+ 2013)
J/A+A/558/A134 : VLTS. 30 Dor luminous stars (Doran+, 2013)
J/A+A/560/A29 : O-stars in VLT-FLAMES Tarantula Survey (Ramirez-Agudelo+ 2013)
J/A+A/564/A39 : VLTS. OVz stars in 30 Dor (Sabin-Sanjulian+, 2014)
J/A+A/564/A40 : VFTS. O-type stellar content of 30 Dor (Walborn+, 2014)
J/A+A/564/L7 : VLT-FLAMES Tarantula Survey: VFTS 822 (Kalari+, 2014)
J/A+A/575/A70 : VFTS. B-type supergiants (McEvoy+, 2015)
J/A+A/580/A93 : VLTS. B stars multiplicity (Dunstall+, 2015)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- VFTS VLT-FLAMES Tarantula Survey identifier
(2011A&A...530A.108E 2011A&A...530A.108E)
5- 21 A17 --- SpType Spectral classification
23- 25 I3 km/s vsini Projected rotational velocity
27- 31 I5 K Teff Effective temperature
33- 36 I4 K e_Teff Mean error on effective temperature
38- 41 F4.2 [cm/s2] logg Surface gravity
43 A1 --- n_logg [*] Note on logg (1)
45- 48 F4.2 [cm/s2] loggc ? Rotation-corrected gravity (G1)
50- 53 F4.2 [cm/s2] e_loggc Mean error on gravity (minimum of 0.10)
55 A1 --- l_Y(He) Limit flag on Y(He)
57- 60 F4.2 --- Y(He) Helium abundance N(He)/N(H) (error=0.02)
62 A1 --- l_logQ Limit flag on logQ
64- 68 F5.1 --- logQ Wind-strength parameter (2)
70- 72 F3.1 --- e_logQ ? Mean error on logQ
74 A1 --- l_logDmom Limit flag on logDmom
76- 79 F4.1 --- logDmom ? Wind momentum (error=0.4)
81- 88 A8 --- Comm Comments regarding possible binarity or
multiplicity (G2)
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Note (1): * for stars with too high gravity (larger than 4.2 dex).
Note (2): Q=(dM/dt)/(vinfR*)^3/2, where dM/dt is the mass-loss rate and
vinf the terminal wind velocity and R the stellar radius.
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- VFTS VLT-FLAMES Tarantula Survey identifier
(2011A&A...530A.108E 2011A&A...530A.108E)
5- 22 A18 --- SpType Spectral classification
24- 26 I3 km/s vsini Projected rotational velocity
28- 32 I5 K Teff Effective temperature
(adopted error of 1500K)
34- 37 F4.2 [cm/s2] logg Surface gravity (adopted error of 0.1)
39- 42 F4.2 [cm/s2] loggc Rotation-corrected gravity (G1)
44 A1 --- l_logQ Limit flag on logQ
46- 50 F5.1 --- logQ Wind-strength parameter
(adopted error of 0.20)
52 A1 --- l_logDmom Limit flag on logDmom
54- 57 F4.1 --- logDmom Wind momentum (error=0.4)
59- 64 A6 --- Comm Comments regarding possible binarity or
multiplicity (G2)
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Byte-by-byte Description of file: tableb1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- VFTS VLT-FLAMES Tarantula Survey identifier
(2011A&A...530A.108E 2011A&A...530A.108E)
5- 21 A17 --- SpType Spectral classification
23- 27 I5 K Teff Effective temperature
29- 32 F4.2 [cm/s2] loggc ? Rotation-corrected gravity (G1)
34- 38 F5.2 mag VMag ? Absolute magnitude in V (G3)
40- 44 F5.2 Rsun R ? Stellar radius
46- 49 F4.2 Rsun e_R ? Mean error in R
51- 54 F4.2 [Lsun] logL ? Stellar luminosity
56- 59 F4.2 [Lsun] e_logL ? Mean error in logL
61- 64 F4.1 Msun Msp ? Spectroscopic mass
66- 69 F4.1 Msun e_Msp ? Mean error in Msp
71- 74 F4.1 Msun Mev(GT) ? Evolutionary mass from Kiel diagram
76- 79 F4.1 Msun e_Mev(GT) ? Mean error on Mev(GT)
81- 84 F4.1 Msun Mev(LT) ? Evolutionary mass from HR diagram
86- 89 F4.1 Msun e_Mev(LT) ? Mean error on Mev(LT)
91- 94 F4.1 Msun Mev(B) ? Evolutionary mass from BONNSAI
(Schneider et al., 2014A&A...570A..66S 2014A&A...570A..66S)
96- 98 F3.1 Msun e_Mev(B) ? Mean error in Mev(B)
100-107 A8 --- Comm Comments regarding possible binarity or
multiplicity (G2)
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Byte-by-byte Description of file: tableb2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- VFTS VLT-FLAMES Tarantula Survey identifier
(2011A&A...530A.108E 2011A&A...530A.108E)
5- 22 A18 --- SpType Spectral classification
24- 28 I5 K Teff Effective temperature
30- 33 F4.2 [cm/s2] loggc Rotation-corrected gravity (G1)
35- 39 F5.2 mag VMag Absolute magnitude in V (G3)
41- 45 F5.2 Rsun R Stellar radius
47- 50 F4.2 [Lsun] logL Stellar luminosity
52- 56 F5.1 Msun Msp Spectroscopic mass
58 A1 --- l_Mev(GT) ? Limit flag on Mev(GT)
60- 62 I3 Msun Mev(GT) Evolutionary mass from Kiel diagram
64- 66 I3 Msun Mev(LT) Evolutionary mass from HR diagram
68- 72 F5.1 Msun Mev(B) Evolutionary mass from BONNSAI
( Schneider et al., 2014A&A...570A..66S 2014A&A...570A..66S)
74- 77 F4.1 Msun e_Mev(B) Mean error in Mev(B)
79- 84 A6 --- Comm Comments regarding possible binarity or
multiplicity (G2)
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Global notes:
Note (G1): loggc=log[g+(vsini)2/R], with R the stellar radius. See
Herrero et al. (1992A&A...261..209H 1992A&A...261..209H) and Repolust et al. (2004A&A...415..349R 2004A&A...415..349R).
Note (G2): Relevant comments from Table 1 in Walborn et al.,
2014A&A...564A..40W 2014A&A...564A..40W.
Note (G3): Absolute magnitudes in the V-band from Maiz Apellaniz et al.
(2014A&A...564A..63M 2014A&A...564A..63M)
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Acknowledgements:
Carolina Sabin-Sanjulian, cssj(at)dfuls.cl
References:
Evans et al., Paper I 2011A&A...530A.108E 2011A&A...530A.108E, Cat. J/A+A/530/108
Taylor et al., Paper II 2011A&A...530L..10T 2011A&A...530L..10T
Bestenlehner et al., Paper III 2011A&A...530L..14B 2011A&A...530L..14B
Bressert et al., Paper IV 2012A&A...542A..49B 2012A&A...542A..49B
Dunstall et al., Paper V 2012A&A...542A..50D 2012A&A...542A..50D
Henault-Brunet et al., Paper VI 2012A&A...545L...1H 2012A&A...545L...1H
Henault-Brunet et al., Paper VII 2012A&A...546A..73H 2012A&A...546A..73H
Sana et al., Paper VIII 2013A&A...550A.107S 2013A&A...550A.107S, Cat. J/A+A/550/A107
van Loon et al., Paper IX 2013A&A...550A.108V 2013A&A...550A.108V, Cat. J/A+A/550/A108
Dufton et al., Paper X 2013A&A...550A.109D 2013A&A...550A.109D, Cat. J/A+A/550/A109
Doran et al., Paper XI 2013A&A...558A.134D 2013A&A...558A.134D, Cat. J/A+A/558/A134
Ramirez-Agudelo et al., Paper XII 2013A&A...560A..29R 2013A&A...560A..29R, Cat. J/A+A/560/A29
Sabin-Sanjulian et al., Paper XIII 2014A&A...564A..39S 2014A&A...564A..39S, Cat. J/A+A/564/A39
Walborn et al., Paper XIV 2014A&A...564A..40W 2014A&A...564A..40W, Cat. J/A+A/564/A40
Kalari et al., Paper XV 2014A&A...564L...7K 2014A&A...564L...7K, Cat. J/A+A/564/L7
Maiz Apellaniz et al., Paper XVI 2014A&A...564A..63M 2014A&A...564A..63M
Bestenlehner et al., Paper XVII 2014A&A...570A..38B 2014A&A...570A..38B
Evans et al., Paper XVIII 2015A&A...574A..13E 2015A&A...574A..13E
McEvoy et al., Paper XIX 2015A&A...575A..70M 2015A&A...575A..70M, Cat. J/A+A/575/A70
Clark et al., Paper XX 2015A&A...579A.131C 2015A&A...579A.131C
Ramirez-Agudelo et al., Paper XXI 2015A&A...580A..92R 2015A&A...580A..92R
Dunstall et al., Paper XXII 2015A&A...580A..93D 2015A&A...580A..93D, Cat. J/A+A/580/A93
Howarth et al., Paper XXIII 2015A&A...582A..73H 2015A&A...582A..73H
(End) C. Sabin-Sanjulian [ULS, Chile] , Patricia Vannier [CDS] 13-Mar-2017