J/A+A/565/A27 Wolf-Rayet stars in Large Magellanic Cloud (Hainich+, 2014)
The Wolf-Rayet stars in the Large Magellanic Cloud. A comprehensive analysis of
the WN class.
Hainich R., Ruehling U., Todt H., Oskinova L.M., Liermann A., Graefener G.,
Foellmi C., Schnurr O., Hamann W.-R.
<Astron. Astrophys., 565, A27-27 (2014)>
=2014A&A...565A..27H 2014A&A...565A..27H
ADC_Keywords: Magellanic Clouds ; Stars, Wolf-Rayet
Keywords: stars: Wolf-Rayet - Magellanic Clouds - stars: early-type -
stars: atmospheres - stars: winds, outflows - stars: mass-loss
Abstract:
Massive stars, although being important building blocks of galaxies,
are still not fully understood. This especially holds true for
Wolf-Rayet (WR) stars with their strong mass loss, whose spectral
analysis requires adequate model atmospheres.
Following our comprehensive studies of the WR stars in the Milky Way,
we now present spectroscopic analyses of almost all known WN stars in
the LMC.
For the quantitative analysis of the wind-dominated emission-line
spectra, we employ the Potsdam Wolf-Rayet (PoWR) model atmosphere
code. By fitting synthetic spectra to the observed spectral energy
distribution and the available spectra (ultraviolet and optical), we
obtain the physical properties of 107 stars.
We present the fundamental stellar and wind parameters for an almost
complete sample of WN stars in the LMC. Among those stars that are
putatively single, two different groups can be clearly distinguished.
While 12% of our sample are more luminous than 106L☉ and
contain a significant amount of hydrogen, 88% of the WN stars, with
little or no hydrogen, populate the luminosity range between
log(L/L☉)=5.3...5.8.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 90 107 Parameters of LMC WN stars
tablea3.dat 33 107 Number of ionizing photons and Zanstra temperatures
for WN stars in the LMC
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- BAT99 BAT99 identification number (Breysacher,
Azzopardi and Testor, 1999A&AS..137..117B 1999A&AS..137..117B)
5- 20 A16 --- SpType Spectral type
22- 25 A4 --- r_SpType Reference for SpType (2)
27- 29 I3 kK T* Stellar (effective) temperature
31- 35 F5.2 [Rsun] logRt transformed radius
37- 40 I4 km/s Vinf Terminal wind velocity V∞
42- 45 F4.2 mag E(B-V) Redenning
47- 51 F5.2 mag VMAG Absolute V magnitude
53- 56 F4.1 Rsun R* Stellar radius
58- 62 F5.2 [Msun/yr] logMdot Mass loss rate
64- 67 F4.2 [Lsun] logL Luminosity
69- 72 F4.1 --- eta Wind efficiency η = (dM/dt)cV∞/L
74- 76 I3 Msun Mass ?=- Stemmar mass (1)
78- 80 F3.1 --- XH [0/1] Hydrogen mass-fraction
82 A1 --- bin [x?] Binarity: x=detected, ?=questionable
83 A1 --- n_bin [c] c: high X-ray emission
85- 90 A6 --- Ref References (2)
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Note (1): Masses calculated from the luminosity, using the mass-luminosity
relation derived by Grafener et al. (2011A&A...535A..56G 2011A&A...535A..56G).
Note (2): References as follows:
1 = BAT99, Breysacher et al., 1999A&AS..137..117B 1999A&AS..137..117B
2 = Foellmi et al. (2003MNRAS.338.1025F 2003MNRAS.338.1025F)
3 = Niemela et al. (2001A&A...369..544N 2001A&A...369..544N)
4 = Niemela et al. (1995IAUS..163..251N 1995IAUS..163..251N)
5 = Koenigsberger et al. (2003RMxAA..39..213K 2003RMxAA..39..213K)
6 = Crowther & Walborn (2011MNRAS.416.1311C 2011MNRAS.416.1311C)
7 = Schnurr et al. (2008MNRAS.389..806S 2008MNRAS.389..806S)
8 = Breysacher (1981A&AS...43..203B 1981A&AS...43..203B)
9 = Smith et al. (1996MNRAS.281..163S 1996MNRAS.281..163S, and references therein)
10 = Moffat (1989ApJ...347..373M 1989ApJ...347..373M)
11 = Crowther et al. (1995A&A...304..269C 1995A&A...304..269C)
12 = Seggewiss et al. (1991A&AS...89..105S 1991A&AS...89..105S)
13 = Niemela (1991IAUS..143..201N 1991IAUS..143..201N)
14 = Crowther & Hadfield (2006A&A...449..711C 2006A&A...449..711C)
15 = Doran et al. (2013A&A...558A.134D 2013A&A...558A.134D, Cat. J/A+A/558/A134)
16 = Evans et al. (2011A&A...530A.108E 2011A&A...530A.108E, Cat. J/A+A/530/A108)
17 = Taylor et al. (2011A&A...530L..10T 2011A&A...530L..10T)
18 = Schnurr et al. (2009MNRAS.397.2049S 2009MNRAS.397.2049S)
19 = Sana et al. (2013MNRAS.432L..26S 2013MNRAS.432L..26S)
20 = Foellmi et al. (2006A&A...460..777G 2006A&A...460..777G)
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Byte-by-byte Description of file: tablea3.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- BAT99 BAT99 identification number
5- 9 F5.2 [ph/s] logQHI ?=- Number of HI ionizing photons (3)
11- 15 I5 K TzHI ?=- Zanstra temperature from HI (3)
17- 21 F5.2 [ph/s] logQHeI ?=- Number of HeI ionizing photons (3)
23- 27 F5.2 [ph/s] logQHeII ?=- Number of HeII ionizing photons (3)
29- 33 I5 K TzHeII ?=- Zanstra temperature from HeII (3)
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Note (3): "---" indicates that only an insignificant number of ionizing
photons can escape the stellar atmosphere.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 24-Jul-2014