J/ApJ/749/177 Yellow and red supergiants in the LMC (Neugent+, 2012)
Yellow and red supergiants in the Large Magellanic Cloud.
Neugent K.F., Massey P., Skiff B., Meynet G.
<Astrophys. J., 749, 177 (2012)>
=2012ApJ...749..177N 2012ApJ...749..177N
ADC_Keywords: Magellanic Clouds ; Stars, giant ; Radial velocities ;
Spectral types ; Spectra, infrared ; Cross identifications
Keywords: galaxies: individual: (LMC) - galaxies: stellar content -
Magellanic Clouds - stars: evolution - supergiants
Abstract:
Due to their transitionary nature, yellow supergiants (YSGs) provide a
critical challenge for evolutionary modeling. Previous studies within
M31 and the Small Magellanic Cloud show that the Geneva evolutionary
models do a poor job at predicting the lifetimes of these short-lived
stars. Here, we extend this study to the Large Magellanic Cloud (LMC)
while also investigating the galaxy's red supergiant (RSG) content.
This task is complicated by contamination by Galactic foreground stars
that color and magnitude criteria alone cannot weed out. Therefore, we
use proper-motions and the LMC's large systemic radial velocity
(∼278km/s) to separate out these foreground dwarfs. After observing
nearly 2000 stars, we identified 317 probable YSGs, 6 possible YSGs,
and 505 probable RSGs. Foreground contamination of our YSG sample was
∼80%, while that of the RSG sample was only 3%. By placing the YSGs on
the Hertzsprung-Russell diagram and comparing them against the
evolutionary tracks, we find that new Geneva evolutionary models do an
exemplary job at predicting both the locations and the lifetimes of
these transitory objects.
Description:
All data were collected using the Cerro Tololo 4m telescope and
Hydra, a 138-fiber multi-object spectrometer with a 2°/3°
field of view. Observations spanned over a clear eight-night run
covering (UT) 2011 January 18-25. (In addition, we used data collected
in 2009 October described by Neugent et al. 2010, Cat. J/ApJ/719/1784).
We used the KPGL-D grating and OG 515 blocking filter in order to
observe the 7700-9200Å region, centered on the CaII triplet
(λλ8498, 8542, 8662), that we intended to use for radial
velocities. This achieved a spectral resolution of 2.6Å (3 binned
pixels).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 126 1447 Properties of observed Yellow Supergiant candidates
table2.dat 122 521 Properties of observed Red Supergiant candidates
table3.dat 123 11 LMC yellow supergiants not observed
table4.dat 33 823 Derived properties of LMC yellow and red supergiants
table5.dat 90 117 Reddest confirmed LMC members in our sample
refs.dat 63 57 References
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See also:
II/322 : OGLE-III. Magellanic Clouds stellar proper motions (Poleski+, 2012)
I/305 : The Guide Star Catalog, Version 2.3.2 (GSC2.3) (STScI, 2006)
II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/236 : UBVR CCD survey of the Magellanic clouds (Massey+, 2002)
III/150 : Perkins Revised MK Types for the Cooler Stars (Keenan+ 1989)
III/147 : Studies of LMC stellar content (Rousseau+ 1978)
J/ApJ/727/53 : Red supergiant stars in the LMC. I. (Yang+, 2011)
J/ApJ/719/1784 : Yellow supergiants in the SMC (Neugent+, 2010)
J/AcA/59/239 : VI LCs of LMC long-period variables (Soszynski+, 2009)
J/ApJ/703/441 : Yellow supergiants in M31 (Drout+, 2009)
J/AN/320/105 : Spectrophot. of 26 LMC supergiants (Oestreicher+ 1999)
J/MNRAS/289/729 : BVRIJHK phot. of red LMC supergiants (Oestreicher+ 1997)
J/AJ/126/2867 : Red supergiants in Magellanic Clouds (Massey+, 2003)
Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS The 2MASS identifier (JHHMMSSss+DDMMSSs)
19 A1 --- n_2MASS [ab] Several observations or literature (1)
21- 22 I2 h RAh Hour of Right Ascension (J2000)
24- 25 I2 min RAm Minute of Right Ascension (J2000)
27- 31 F5.2 s RAs Second of Right Ascension (J2000)
33 A1 --- DE- [-] Sign of the Declination (J2000)
34- 35 I2 deg DEd Degree of Declination (J2000)
37- 38 I2 arcmin DEm Arcminute of Declination (J2000)
40- 43 F4.1 arcsec DEs Arcsecond of Declination (J2000)
45- 50 I6 --- M2002 ? Massey 2002, Cat. II/236 designation (2)
52- 56 F5.2 mag Ksmag [5.1/12.6]? 2MASS Ks band magnitude
58- 61 F4.2 mag J-Ks [0/1.7] 2MASS (J-Ks) color index
63- 67 F5.2 mag Vmag [8/17]? The V band magnitude
69 A1 --- r_Vmag [c] Vmag and (B-V) from literature (3)
71- 75 F5.2 mag B-V [-0.2/3.1]? The (B-V) color index
77 A1 --- r_B-V [c] Vmag and (B-V) from literature (3)
79- 82 F4.2 mag V-R [0/2]? The (V-R) color index
84- 88 F5.1 km/s RV [-57.1/401] Radial velocity
90- 94 F5.1 --- r [12/168] Tonry & Davis 1979AJ.....84.1511T 1979AJ.....84.1511T
cross-correlation r parameter
96 I1 --- Cat [1/3] Category (1=ok) (4)
98-105 A8 --- SpT MK spectral type
107-108 I2 --- r_SpT ? Reference for SpT (see refs.dat file)
110-126 A17 --- Comm Additional comment or identification
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Note (1): Flag as follows:
a = These stars were observed spectroscopically twice, and their RVel and
r values averaged.
b = Radial velocity also obtained by Massey & Olsen 2003, Cat. J/AJ/126/2867
Note (2): If there is a M2002 designation, the photometry is from
Massey 2002, Cat. II/236; <[M2002] LMC NNNNNN> in Simbad.
If there is not, the photometry is from the same source of the
spectral type unless otherwise noted.
Note (3):
c = Oestreicher et al. 1997, Cat. J/MNRAS/289/729.
Note (4): Category as follows:
1 = LMC supergiant;
2 = possible LMC supergiant;
3 = foreground dwarf.
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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- 17 A17 --- 2MASS 2MASS name (JHHMMSSss+DDMMSSs)
19- 20 I2 h RAh Hour of right ascension (J2000)
22- 23 I2 min RAm Minute of right ascension (J2000)
25- 29 F5.2 s RAs Second of right ascension (J2000)
31 A1 --- DE- Sign of declination (J2000)
32- 33 I2 deg DEd Degree of declination (J2000)
35- 36 I2 arcmin DEm Arcminute of declination (J2000)
38- 41 F4.1 arcsec DEs Arcsecond of declination (J2000)
43- 47 F5.2 mag Ksmag [7.4/13.5] 2MASS Ks-band magnitude
49- 52 F4.2 mag J-Ks [0.04/0.6] 2MASS (J-Ks) color index
54- 57 F4.1 mag Vmag [9.7/13.2] V-band magnitude
59- 63 A5 --- SpT MK spectral type from literature
65 I1 --- f_SpT [1/5] Reference (1)
67- 87 A21 --- AName Alternative(s) name(s)
89-123 A35 --- Comm Comments
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Note (1): References for spectral classifications and V magnitudes as follows:
1 = Ardeberg et al. 1972A&AS....6..249A 1972A&AS....6..249A
2 = Feast et al. 1960MNRAS.121..337F 1960MNRAS.121..337F
3 = Keenan & McNeil, Cat. III/150
4 = Melnick 1985A&A...153..235M 1985A&A...153..235M
5 = Rousseau et al. 1978, Cat. III/147
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS The 2MASS identifier (JHHMMSSss+DDMMSSs)
19 I1 --- Cat [1/2] Category, 1=ok (1)
21- 25 F5.3 [K] logTe [3.4/4.1] Log of the effective temperature
27- 31 F5.3 [Lsun] logL [2.6/5.8] Log of the luminosity
33 A1 --- Col [RY] Color; Y=Yellow, R=Red
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Note (1): Category as follows:
1 = LMC supergiant;
2 = possible LMC supergiant.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 17 A17 --- 2MASS The 2MASS identifier (JHHMMSSss+DDMMSSs)
19- 23 F5.2 mag Ksmag [7.4/10.3] 2MASS Ks band magnitude
25- 28 F4.2 mag J-Ks [1/2] 2MASS (J-Ks) color index
30- 34 F5.2 mag Vmag [12/17]? The V band magnitude (1)
36 A1 --- f_Vmag [fgh] Flag on Vmag (2)
38- 40 F3.1 mag V-Ks [4/7]? The (V-Ks) color index
42- 47 I6 --- M2002 ? Massey 2002, Cat. II/236, designation
49- 51 A3 --- 10um [AIM ] 10µm detection in AKARI, IRAS, MSX
53- 59 A7 --- SpT MK spectral type; same as in Table 1
61- 76 A16 --- Var Variability (4)
78- 90 A13 --- OID Other identifier
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Note (1): From Massey 2002, Cat. II/236, unless otherwise noted.
Note (2): Vmag flag as follows:
f = V magnitude from GSC-2.3 (Cat. I/305) based upon a short-V plate taken
with the UK Schmidt, and may be slightly brighter than standard V.
g = V magnitude from OGLE database (Soszynski et al., 2009,
Cat. J/AcA/59/239).
h = V magnitude from ASAS-3 (Pojmanski, 1997AcA....47..467P 1997AcA....47..467P ; Cat. II/264).
Note (4): Variability based primarily upon the OGLE database (Soszynski et
al., 2009, Cat. J/AcA/59/239), but the OGLE period (in days) is quoted
only if the light curve appeared reasonably smooth. The CGVS and ASAS
were used as indicated. Final notes in the comment mean:
i = Shorter cycles superposed.
j = Slow variable of 0.7 mag range.
k = Period confirmed in ASAS database.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode Bibcode
24- 44 A21 --- Aut Author's name(s)
46- 63 A18 --- Comm VizieR catalog reference
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 03-Dec-2013