J/AJ/154/102 LMC blue supergiants spectroscopic observations (Urbaneja+, 2017)
LMC blue supergiant stars and the calibration of the Flux-weighted
Gravity-Luminosity Relationship.
Urbaneja M.A., Kudritzki R.-P., Gieren W., Pietrzynski G., Bresolin F.,
Przybilla N.
<Astron. J., 154, 102-102 (2017)>
=2017AJ....154..102U 2017AJ....154..102U (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Stars, supergiant ; Stars, blue ;
Spectral types ; Effective temperatures ; Abundances ;
Photometry, UBV ; Photometry, infrared
Keywords: galaxies: distances and redshifts - galaxies: individual (LMC) -
stars: early-type - supergiants
Abstract:
High-quality spectra of 90 blue supergiant stars in the Large Magellanic
Cloud are analyzed with respect to effective temperature, gravity,
metallicity, reddening, extinction, and extinction law. An average
metallicity, based on Fe and Mg abundances, relative to the Sun of
[Z]=-0.35±0.09 dex is obtained. The reddening distribution peaks at
E(B-V)=0.08 mag, but significantly larger values are also encountered.
A wide distribution of the ratio of extinction to reddening is found
ranging from RV=2 to 6. The results are used to investigate the blue
supergiant relationship between flux-weighted gravity, gF=g/Teff4,
and absolute bolometric magnitude Mbol. The existence of a tight
relationship, the Flux-weighted Gravity-Luminosity Relationship (FGLR),
is confirmed. However, in contrast to previous work, the observations
reveal that the FGLR is divided into two parts with a different slope.
For flux-weighted gravities larger than 1.30 dex, the slope is similar
to that found in previous work, but the relationship becomes significantly
steeper for smaller values of the flux-weighted gravity. A new calibration
of the FGLR for extragalactic distance determinations is provided.
Description:
We present new spectroscopic observations of a sample of 32 blue
supergiants obtained with the Magellan Echellete spectrograph. Our core
sample is complemented with spectra of another 58 LMC supergiant stars
collected from other sources.
Optical spectra of 32 LMC blue supergiant stars were collected during
the nights of 2008 October 29th and 30th, and 2010 November 10th, using
the Magellan Echellete spectrograph (MagE, Marshall et al.
2008SPIE.7014E..54M 2008SPIE.7014E..54M), a medium-resolution, cross-dispersed, optical
spectrograph on the Clay Telescope at Las Campanas Observatory. We
selected the 1 arcsec slit, providing a nominal resolving power of
R∼4100. MagE has a plate scale of 0.3 arsec/pixel, and it covers a
wide spectral range, ∼3100-10000 Å.
Objects:
---------------------------------------------------------------
RA (ICRS) DE Designation(s)
---------------------------------------------------------------
05 23 34.6 -69 45 22 LMC = NAME Large Magellanic Cloud
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table11.dat 80 90 LMC Supergiants - Optical Photometry
table12.dat 70 87 LMC Supergiants - 2MASS Photometry
(Skrutskie et al. 2006, Cat. VII/233)
table13.dat 83 87 LMC Supergiants - IRAC Photometry
(Meixner et al. 2006, J/AJ/132/2268)
table1.dat 67 23 LMC BA Supergiants Observed with MagE
table2.dat 67 23 LMC OB Supergiants (MagE and FLAMES I)
table3.dat 67 29 LMC OB Supergiants (FEROS)
table4.dat 67 15 LMC VFTS OB Supergiants
table6.dat 138 23 LMC BA Supergiants Results
table7.dat 138 23 LMC OB Supergiants Results (MagE and FLAMES I)
table8.dat 138 29 LMC OB Supergiants Results (FEROS)
table9.dat 138 15 LMC VFTS OB Supergiants Results
table10.dat 63 17 BA Supergiants Results Based on the Balmer Jump
as Teff Indicator, at Nominal and Degraded
Spectral Resolution
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See also:
VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)
J/A+AS/24/35 : LMC A-F supergiants (Stock+, 1976)
J/A+AS/35/347 : OB and Supergiants stars in LMC (Philip+, 1979)
J/AN/320/105 : Spectrophotometry of 26 supergiants in the LMC
(Oestreicher+ 1999)
J/A+A/456/623 : VLT-FLAMES survey of massive stars (Evans+, 2006)
J/AJ/132/2268 : SAGE calibration stars (Meixner+, 2006)
J/A+A/575/A70 : VLT-FLAMES Tarantula Survey: B supergiants (McEvoy+, 2015)
Byte-by-byte Description of file: table11.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Star Star name
13- 17 F5.2 mag Vmag [9.87/15.53] Johnson V band magnitude (1)
19- 23 F5.2 mag B-V [-0.2/0.5] Johnson B-V color index (1)
25- 29 F5.2 mag U-B [-0.98/0.2]? Johnson U-B color index (1)
31- 60 A30 --- Ref Reference
62- 80 A19 --- BibCode BibCode of the reference
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Note (1): Unfortunately, individual errors in the photometric measurements for
the full sample are not readily available. Many of the works do not provide
this valuable information. In what follows, we list the uncertainties quoted
in those references listed:
(a) Ardeberg et al. (1972A&AS....6..249A 1972A&AS....6..249A): sig(V)=0.017, sig(B-V)=0.013,
sig(U-B)=0.017;
(b) Isserstedt (1975A&AS...19..259I 1975A&AS...19..259I, 1979A&AS...38..239I 1979A&AS...38..239I,
1982A&AS...50....7I 1982A&AS...50....7I): sig(V)=0.025, sig(B-V)=0.020, sig(U-B)= 0.025;
(c) Nicolet (1978A&AS...34....1N 1978A&AS...34....1N): sig(V)=0.02, sig(B-V)=0.015, sig(U-B)=0.02;
(d) Gordon et al. (2003ApJ...594..279G 2003ApJ...594..279G) - for Sk-68 26: sig(V)=0.003,
sig(B-V)=0.002, sig(U-B)=0.001.
In lieu of this information being missing for all other references, we adopted
a flat error of sig(B-V)=0.02 mag and sig(V)=0.02 mag for all of the optical
photometry used in this work.
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Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Star Star name
13- 31 A19 --- ID SSTISAGEMC identifier (JHHMMSS.ss+DDMMSS.s)
33- 38 F6.3 mag Jmag [9.604/14.698]? 2MASS J band magnitude
40- 44 F5.3 mag e_Jmag [0.02/0.038]? Uncertainty in Jmag
46- 51 F6.3 mag Hmag [9.54/14.715]? 2MASS H band magnitude
53- 57 F5.3 mag e_Hmag [0.01/0.05]? Uncertainty in Hmag
59- 64 F6.3 mag Ksmag [9.474/14.686]? 2MASS KS band magnitude
66- 70 F5.3 mag e_Ksmag [0.019/0.063]? Uncertainty in Ksmag
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Byte-by-byte Description of file: table13.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 A11 --- Star Star name
13- 31 A19 --- ID SSTISAGEMC identifier (JHHMMSS.ss+DDMMSS.s)
33- 38 F6.3 mag 3.6mag [9.272/14.655]? Spitzer/IRAC 3.6µm band
magnitude
40- 44 F5.3 mag e_3.6mag [0.019/0.069]? Uncertainty in 3.6mag
46- 51 F6.3 mag 4.5mag [9.246/14.646]? Spitzer/IRAC 4.5µm band
magnitude
53- 57 F5.3 mag e_4.5mag [0.017/0.071]? Uncertainty in 4.5mag
59- 64 F6.3 mag 5.8mag [9.197/14.601]? Spitzer/IRAC 5.8µm band
magnitude
66- 70 F5.3 mag e_5.8mag [0.02/0.163]? Uncertainty in 5.8mag
72- 77 F6.3 mag 8.0mag [9.152/12.996]? Spitzer/IRAC 8.0µm band
magnitude
79- 83 F5.3 mag e_8.0mag [0.022/0.127]? Uncertainty in 8.0mag
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Byte-by-byte Description of file: table[1234].dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Star Star name
13- 14 I2 h RAh Hour of Right Ascension (J2000)
16- 17 I2 min RAm Minute of Right Ascension (J2000)
19- 26 F8.5 s RAs Second of Right Ascension (J2000)
28 A1 --- DE- Sign of the Declination (J2000)
29- 30 I2 deg DEd Degree of Declination (J2000)
32- 33 I2 arcmin DEm Arcminute of Declination (J2000)
35- 41 F7.4 arcsec DEs Arcsecond of Declination (J2000)
43- 47 F5.2 mag Vmag [9.87/15.53] V band magnitude
49- 63 A15 --- SpType MK spectral type
65- 67 A3 --- r_SpType Reference for SpType (1)
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Note (1): Reference as follows:
tw = This work;
A72 = Ardeberg et al. (1972A+AS....6..249A 1972A+AS....6..249A);
E06 = Evans et al. (2006, J/A+A/456/623);
F88 = Fitzpatrick (1988ApJ...335..703F 1988ApJ...335..703F);
S76 = Stock et al. (1976, J/A+AS/24/35);
F91 = Fitzpatrick (1991PASP..103.1123F 1991PASP..103.1123F);
W02 = Walborn et al. (2002ApJS..141..443W 2002ApJS..141..443W);
F87 = Fitzpatrick (1987ApJ...312..596F 1987ApJ...312..596F);
M95 = Massey et al. (1995ApJ...438..188M 1995ApJ...438..188M);
M10 = Massey (2010ASPC..425....3M 2010ASPC..425....3M).
Reference for the spectral classification in Table 4: McEvoy et al. (2015,
J/A+A/575/A70).
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Byte-by-byte Description of file: table[6789].dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Star Star name
13- 18 F6.4 10+4K Teff [0.8465/2.7] Effective temperature
20- 25 F6.4 10+4K e_Teff [0.0030/0.0755] Lower limit uncertainty in Teff
27- 32 F6.4 10+4K E_Teff [0.0035/0.081] Upper limit uncertainty in Teff
34- 37 F4.2 [-] loggF [1.10/1.95] Log of flux-weighted gravity (dex)
39- 42 F4.2 [-] e_loggF [0.01/0.09] Lower limit uncertainty in loggF
(dex)
44- 47 F4.2 [-] E_loggF [0.01/0.08] Upper limit uncertainty in loggF
(dex)
49- 52 F4.2 [-] [Mg/H] [6.92/7.49] Mg abundance (dex)
54- 57 F4.2 [-] e_[Mg/H] [0.04/0.27] Lower limit uncertainty in [Mg/H]
(dex)
59- 62 F4.2 [-] E_[Mg/H] [0.04/0.27] Upper limit uncertainty in [Mg/H]
(dex)
64- 67 F4.2 [-] [Fe/H] [7.01/7.31]? Fe abundance (dex) (only in Table 6)
69- 72 F4.2 [-] e_[Fe/H] [0.05/0.18]? Lower limit uncertainty in [Fe/H]
(dex) (only in Table 6)
74- 77 F4.2 [-] E_[Fe/H] [0.08/0.21]? Upper limit uncertainty in [Fe/H]
(dex) (only in Table 6)
79- 83 F5.2 mag BC [-2.66/-0.01] Bolometric correction
85- 88 F4.2 mag e_BC [0.01/0.06] Uncertainty in BC
90- 93 F4.2 mag E(B-V) [0.03/0.64] Reddening
95- 98 F4.2 mag e_E(B-V) [0.01/0.04] Lower limit uncertainty in E(B-V)
100-103 F4.2 mag E_E(B-V) [0.01/0.04] Upper limit uncertainty in E(B-V)
105-108 F4.2 --- RV [1.27/8.52] Ratio of visual extinction to
reddening RV=AV/E(B-V)
110-113 F4.2 --- e_RV [0.21/2.98] Lower limit uncertainty in RV
115-118 F4.2 --- E_RV [0.19/2.37] Upper limit uncertainty in RV
120-123 F4.2 mag AV [0.13/2.31] Visual extinction
125-128 F4.2 mag e_AV [0.03/0.06] Lower limit uncertainty in AV
130-133 F4.2 mag E_AV [0.03/0.06] Upper limit uncertainty in AV
135-138 F4.2 --- chi2 [0.06/3.04] Final reduced-χ2 value
resulting from the RV-E(B-V) analysis
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Star Star name
12- 15 F4.2 --- DB [0.16/0.62] Balmer jump DB index (dex) (1)
17- 22 F6.4 10+4K Teff1 [0.834/1.23] Effective temperature derived at
nominal spectral resolution
24- 29 F6.4 10+4K e_Teff1 [0.0045/0.0375] Uncertainty in Teff1
31- 34 F4.2 [-] loggF1 [1.24/1.91] Log of flux-weighted gravity derived
at nominal spectral resolution (dex)
36- 39 F4.2 [-] e_loggF1 [0.03/0.07] Uncertainty in loggF1 (dex)
41- 46 F6.4 10+4K Teff2 [0.8535/1.2375] Effective temperature derived at
degraded spectral resolution
48- 53 F6.4 10+4K e_Teff2 [0.0103/0.0301] Uncertainty in Teff2
55- 58 F4.2 [-] loggF2 [1.24/1.9] Log of flux-weighted gravity derived
at degraded spectral resolution (dex)
60- 63 F4.2 [-] e_loggF2 [0.01/0.09] Uncertainty in loggF2 (dex)
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Note (1): The uncertainty in the measured DB index at the nominal resolution
is in all cases smaller than 0.01 dex. See text for details.
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 19-Jul-2018