J/AJ/129/1465 Spectroscopy of red giants in the LMC bar (Cole+, 2005)
Spectroscopy of red giants in the Large Magellanic Cloud bar: abundances,
kinematics, and the age-metallicity relation.
Cole A.A., Tolstoy E., Gallagher J.S.III, Smecker-Hane T.A.
<Astron. J., 129, 1465-1482 (2005)>
=2005AJ....129.1465C 2005AJ....129.1465C
ADC_Keywords: Magellanic Clouds ; Stars, giant ; Radial velocities ; Abundances
Keywords: galaxies: evolution - galaxies: stellar content - Magellanic Clouds
Abstract:
We report metallicities and radial velocities derived from spectra at
the near-infrared calcium triplet for 373 red giants in a 200arcmin2
area at the optical center of the LMC bar. These are the first
spectroscopic abundance measurements of intermediate-age and old field
stars in the high surface brightness heart of the LMC. The metallicity
distribution is sharply peaked at the median value [Fe/H]=-0.40,
with a small tail of stars extending down to [Fe/H]≤-2.1; 10% of the
red giants are observed to have [Fe/H]≤-0.7.
Description:
The spectroscopic observations were made in Visitor Mode at the Yepun
(VLT-UT4) 8.2m telescope at ESO's Paranal Observatory, on the nights
of 2002 December 24-26.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table2.dat 100 373 Data for red giants in the bar field
table3.dat 45 373 Derived quantities for red giants in the bar field
--------------------------------------------------------------------------------
See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
J/AJ/120/1808 : Stroemgren photometry in LMC disk (Cole+, 2000)
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS The 2MASS identification (G1)
18- 21 A4 --- Field Field identification
23- 28 F6.3 mag Vmag The V band magnitude
30- 34 F5.3 mag e_Vmag The 1σ error in Vmag
36- 41 F6.3 mag Imag The I band magnitude
43- 47 F5.3 mag e_Imag The 1σ error in Imag
49- 53 F5.1 km/s RV Heliocentric velocity
55- 57 F3.1 km/s e_RV The 1σ error in RV
59- 62 F4.2 0.1nm EW Summed 3 Ca II triplet equivalent width in
units of Angstroms (1)
64- 67 F4.2 0.1nm e_EW The 1σ error in EW
68-100 A33 --- Note Additional note
--------------------------------------------------------------------------------
Note (1): Of the three lines ranged from 3.5Å≤EW≤10Å, with typical
errors of ∼2%.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 16 A16 --- 2MASS The 2MASS Identification (G1)
18- 22 F5.2 [Sun] [Fe/H] Log of Fe/H number abundance
24- 27 F4.2 [Sun] e_[Fe/H] The 1σ error in [Fe/H]
29- 33 F5.2 [Sun] [a/Fe] Log of (α-process elements)/Fe number
abundance
35- 39 F5.2 [yr] log(Age) Log of the age
41- 44 F4.2 [yr] e_log(Age) The 1σ error in log(Age)
--------------------------------------------------------------------------------
Global Notes:
Note (G1): Except where an unambiguous identification was not possible;
in these cases the number from the OGLE-II catalog.
--------------------------------------------------------------------------------
History:
From electronic version of the journal
References:
Cole et al., 2000AJ....120.1808C 2000AJ....120.1808C, Cat. J/AJ/120/1808
Cole et al., 2004MNRAS.347..367C 2004MNRAS.347..367C
Smecker-Hane et al., 2004, ApJ, submitted
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 22-Aug-2005