J/AJ/142/61 RGB stars in LMC outer disk (Carrera+, 2011)
Metallicities, age-metallicity relationships, and kinematics of red giant branch
stars in the outer disk of the Large Magellanic Cloud.
Carrera R., Gallart C., Aparicio A., Hardy E.
<Astron. J., 142, 61 (2011)>
=2011AJ....142...61C 2011AJ....142...61C
ADC_Keywords: Magellanic Clouds ; Stars, giant ; Photometry ; Spectroscopy
Keywords: galaxies: abundances - galaxies: evolution -
galaxies: kinematics and dynamics - galaxies: stellar content -
Magellanic Clouds
Abstract:
The outer disk of the Large Magellanic Cloud (LMC) is studied in order
to unveil clues about its formation and evolution. Complementing our
previous studies in innermost fields (3kpc≲R≲7kpc), we
obtained deep color-magnitude diagrams in six fields with
galactocentric distances from 5.2kpc to 9.2kpc and different
azimuths. The comparison with isochrones shows that while the oldest
population is approximately coeval in all fields, the age of the
youngest populations increases with increasing radius. This agrees
with the results obtained in the innermost fields. Low-resolution
spectroscopy in the infrared CaII triplet region has been obtained
for about 150 stars near the tip of the red giant branch in the same
fields. Radial velocities and stellar metallicities have been obtained
from these spectra. The metallicity distribution of each field has
been analyzed together with those previously studied.
Description:
V- and I-band images for the northern fields, and B- and R-band images
for the others, were obtained with the Wide Field Imager (WFI) at the
2.2m telescope at La Silla Observatory, Chile.
The spectroscopic observations were carried out in service mode on ESO
period 82 with FLAMES mounted at Very Large Telescope (VLT) UT2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 78 249 LMC RGB stars observed
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See also:
J/A+A/480/379 : Abundances of 59 red giants in LMC (Pompeia+, 2008)
J/AJ/139/878 : RGB stars in 8 LMC clusters (Sharma+, 2010)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Hour of Right Ascension (J2000)
4- 5 I2 min RAm Minute of Right Ascension (J2000)
7- 11 F5.2 s RAs Second of Right Ascension (J2000)
13 A1 --- DE- Sign of the Declination (J2000)
14- 15 I2 deg DEd Degree of Declination (J2000)
17- 18 I2 arcmin DEm Arcminute of Declination (J2000)
20- 23 F4.1 arcsec DEs Arcsecond of Declination (J2000)
25- 30 F6.3 0.1nm W(CaT) The Ca II triplet lines index ΣCa (1)
32- 36 F5.3 0.1nm e_W(CaT) Uncertainty in SigmaCa
38- 44 F7.4 mag BVmag The B or V band magnitude (2)
46- 52 F7.4 mag Imag The I band magnitude
54- 61 F8.4 km/s RV Radial velocity
63- 68 F6.3 km/s e_RV Uncertainty in RV
70- 78 A9 --- Com Comments
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Note (1): Defined as the sum of the equivalent widths of the three lines.
Note (2): V magnitude for northern field (-61≤DE≤-59),
B magnitude for eastern and western fields (-71≤DE≤-70).
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History:
From electronic version of the journal
References:
Gallart et al., Paper I 2008ApJ...682L..89G 2008ApJ...682L..89G
Carrera et al., Paper II 2008AJ....135..836C 2008AJ....135..836C, Cat. J/AJ/135/836
Carrera et al., Paper III 2007AJ....134.1298C 2007AJ....134.1298C, Cat. J/AJ/134/1298
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 12-Oct-2012