J/A+A/575/A70 VLT-FLAMES Tarantula Survey: B supergiants (McEvoy+, 2015)
The VLT-FLAMES Tarantula Survey.
XIX. B-type supergiants: Atmospheric parameters and nitrogen abundances to
investigate the role of binarity and the width of the main sequence.
McEvoy C.M., Dufton P.L., Evans C.J., Kalari V.M., Markova N.,
Simon-Diaz S., Vink J.S., Walborn N.R., Crowther P.A., De Koter A.,
de Mink S.E., Dunstall P.R., Henault-Brunet V., Herrero A., Langer N.,
Lennon D.J., Maiz Apellaniz J., Najarro F., Puls J., Sana H.,
Schneider F.R.N., Taylor W.D.
<Astron. Astrophys., 575, A70-70 (2015)>
=2015A&A...575A..70M 2015A&A...575A..70M
ADC_Keywords: Stars, B-type ; Stars, supergiant ;
Keywords: stars: early-type - supergiants - stars: rotation -
Magellanic Clouds -
open clusters and associations: individual: Tarantula Nebula -
stars: atmospheres
Abstract:
Model atmosphere analyses have been previously undertaken for both
Galactic and extragalactic B-type supergiants. By contrast, little
attention has been given to a comparison of the properties of single
supergiants and those that are members of multiple systems.
Atmospheric parameters and nitrogen abundances have been estimated for
all the B-type supergiants identified in the VLT-FLAMES Tarantula
survey. These include both single targets and binary candidates. The
results have been analysed to investigate the role of binarity in the
evolutionary history of supergiants. TLUSTY non-local thermodynamic
equilibrium (LTE) model atmosphere calculations have been used to
determine atmospheric parameters and nitrogen abundances for 34 single
and 18 binary supergiants. Effective temperatures were deduced using
the silicon balance technique, complemented by the helium ionisation
in the hotter spectra. Surface gravities were estimated using Balmer
line profiles and microturbulent velocities deduced using the silicon
spectrum. Nitrogen abundances or upper limits were estimated from the
NII spectrum. The effects of a flux contribution from an unseen
secondary were considered for the binary sample. We present the first
systematic study of the incidence of binarity for a sample of B-type
supergiants across the theoretical terminal age main sequence (TAMS).
Description:
The majority of the VFTS data were obtained using the Medusa mode of
FLAMES, which uses fibres to feed the light from up to 130 targets
simultaneously to the Giraffe spectrograph. Nine Medusa configurations
(Fields A to I) were observed in the 30 Dor region, with the targets
sampling its different clusters and the local field population.
The analysis presented here employs the FLAMES-Medusa observations
obtained with two of the standard Giraffe settings (LR02 and LR03),
giving coverage of the λλ3960-5050Å region at a
resolving power of ∼7000.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 58 54 Binarity status, spectral classifications and
typical signal-to-noise ratios of the
VFTS B-type supergiant sample
table2.dat 27 33 Estimates for atmospheric parameters for the
single stars
table3.dat 33 18 Estimates for atmospheric parameters of the
binary stars
table4.dat 81 52 Adopted estimates for the projected rotational
velocity (v.sini), atmospheric parameters and
nitrogen abundances
table7.dat 66 52 Estimates of the stellar luminosity (L) and
spectroscopic mass (Ms) for our sample
--------------------------------------------------------------------------------
See also:
J/A+A/530/A108 : VLT-FLAMES Tarantula Survey (Evans+, 2011)
J/A+A/550/A107 : 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 : VLT-FLAMES Tarantula Survey: vsini measures (Dufton+ 2013)
J/A+A/564/L7 : VLT-FLAMES Tarantula Survey: VFTS 822 (Kalari+, 2014)
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/574/A13 : VFTS. B-type stars classification and RV (Evans+, 2015)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Star [3/867] Star VFTS number
5- 14 A10 --- OName Other name of star
16- 18 I3 km/s DRV [2/404] Variation in radial velocities
20- 22 A3 --- BinD15 Binary status from Dunstall et al., in prep. (2)
24- 26 A3 --- BinM Binary status from moment analysis (2)
28- 30 A3 --- Bin Adopted binary status (2)
32- 48 A17 --- SpType MK spectral type (1)
50 A1 --- n_SpType [+] + for SpType from Walborn et al.
(2014A&A...564A..40W 2014A&A...564A..40W)
52- 54 I3 --- SN2 [50/650] Typical S/N for LR02 Giraffe setting
56- 58 I3 --- SN3 [40/440] Typical S/N for LR03 Giraffe setting
--------------------------------------------------------------------------------
Note (1): taken from Evans et al. 2015A&A...574A..13E 2015A&A...574A..13E, Cat. J/A+A/574/A13,
or from Walborn et al. (2014A&A...564A..40W 2014A&A...564A..40W, Cat. J/A+A/564/A40)
if n_SpType = +.
Note (2): the status can be S=Single, SB1 (single-spectrum spectroscopic
binary), or SB2 (double-spectrum spectroscopic binary)
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Star [3/867] Star VFTS number
4 A1 --- Note [*] * if atmospheric parameter estimates
found from extrapolation
6- 10 I5 K Te.Si [12000/29000] Effective temperature estimated
from the Silicon ionisation balance (Si)
12- 16 I5 K Te.He [23000/28500]?=- Effective temperature estimated
from HeII profile at 4686Å
18- 21 F4.2 [cm/s2] logg [1.6/3.3] Surface gravity
23- 24 I2 km/s vt1 [6/16]? Microturbulence velocity estimated from
relative strength of the SiIII lines
26- 27 I2 km/s vt2 [0/21]? Microturbulence velocity estimated from
absolute silicon abundance
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Star [3/867] Star VFTS number
4 A1 --- f_Te.Si [*+] Extrapolated or constrained temperature (1)
6- 10 I5 K Te.Si [13500/29000] Effective temperature estimated
from the silicon ionisation balance (Si)
12- 16 I5 K Te.He1 [21500/28500]?=- Effective temperature estimated
from HeII profile at 4686Å
18- 22 I5 K Te.He2 [24000/29500]?=- Effective temperature estimated
from HeII profile at 4541Å
24- 27 F4.2 [cm/s2] logg [2.3/3.3] Surface gravity
29- 30 I2 km/s vt1 [5/18]? Microturbulence velocity estimated from
relative strength of the SiIII lines
32- 33 I2 km/s vt2 [0/30]? Microturbulence velocity estimated from
absolute silicon abundance
--------------------------------------------------------------------------------
Note (1): the flag has the following meaning:
* = atmospheric parameter estimates found from extrapolation
+ = Teff constrained by absence of SiII and SiIV spectra
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Star [3/867] Star VFTS number
5- 21 A17 --- SpType2 MK Spectral type
23- 25 I3 km/s RV [202/343] Radial velocity (3)
27 A1 --- n_RV [1] Origin of RV (4)
29- 30 A2 --- l_vsini [≤ ] Limit flag on vsini
31- 33 I3 km/s vsini Projected rotational velocity
35 A1 --- n_vsini [2] Origin of vsini (4)
36- 37 I2 km/s vsini2 ? FT estimate of projected rotational velocity
for low S/N cases
40- 44 I5 K Teff [12000/29500] Effective temperature
46- 49 F4.2 [cm/s2] logg [1.6/3.3] Surface gravity
51- 52 I2 km/s vt [0/30] Microturbulence velocity
54- 57 F4.2 [-] Mg [6.5/7.5]?=- Mg abundance (scale log(X/H)+12)
59- 60 A2 --- l_N3995 [≤ ] Limit flag on l3995
61- 64 F4.2 [-] N3995 [6.8/8.3] Abundance of N from λ3995Å
(scale log(X/H)+12)
66- 69 F4.2 [-] N [6.8/8.3]?=- Total N abundance
(scale log(X/H)+12)
71- 74 F4.2 [-] e_N ? rms uncertainty on N
76 I1 --- nN ? Number of line used for total N abundance
78- 81 F4.2 [Lsun] logLe [3.4/4.4] Star luminosity (5)
--------------------------------------------------------------------------------
Note (3): from Evans et al. (2015A&A...574A..13E 2015A&A...574A..13E, Cat. J/A+A/574/A13) and
Sana et al. (2013A&A...550A..10L 2013A&A...550A..10L).
Note (4): Notes as follows:
1 = Systematic velocity from orbital solution, see Howarth et al. (in prep.).
2 = Taken from Dufton et al. (2013A&A...550A.109D 2013A&A...550A.109D, Cat. J/A+A/550/A109)
Note (5): logLe is proportional to the Eddington factor, where L=Teff4/g
and has a maximum value of 4.6dex (corresponding to the Eddington limit) for
a normal helium to hydrogen ratio (Langer & Kudritzki, 2014A&A...564A..52L 2014A&A...564A..52L).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table7.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Star [3/867] Star VFTS number
5- 21 A17 --- SpType2 MK spectral type
23- 26 F4.2 mag AkV [0/0.6]?=- VISTA infrared extinction
28- 31 F4.2 mag Ak2 [0/0.6]?=- 2MASS Ks-band extinction
33- 36 F4.2 [Lsun] logLv [3.9/6.0]?=- Visible stellar luminosity
38- 41 F4.2 [Lsun] logLV [4.2/5.7]?=- VISTA stellar luminosity
43- 46 F4.2 [Lsun] logL2 [4.2/6.2]?=- 2MASS stellar luminosity
48- 51 F4.2 [Lsun] logL [4.2/6.1]?=- Adopted stellar luminosity
53- 54 I2 Msun Ms [4/71] Spectroscopic mass
56- 57 I2 Msun Me [12/48]?=- Current evolutionary mass estimate
59 A1 --- l_Mo [>] Limit flag on Mo
60- 61 I2 Msun Mo [13/60]?=- Initial evolutionary mass estimate
63- 66 F4.2 [yr] logt [6.5/7.2]?=- Stellar age
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Evans et al., Paper I 2011A&A...530A.108E 2011A&A...530A.108E, Cat. J/A+A/530/A108
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
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, Cat. J/A+A/574/A13
(End) Patricia Vannier [CDS] 03-Jun-2015