J/MNRAS/450/2122 CCD photometry of star clusters in the LMC (Palma+, 2015)
Probing the Large Magellanic Cloud's recent chemical enrichment history through
its star clusters.
Palma T., Claria J.J., Geisler D., Gramajo L.V., Ahumada A.V.
<Mon. Not. R. Astron. Soc., 450, 2122-2131 (2015)>
=2015MNRAS.450.2122P 2015MNRAS.450.2122P (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Clusters, open ; Photometry, CMT1T2V
Keywords: techniques: photometric - galaxies: individual: LMC -
galaxies: star clusters: general
Abstract:
We present Washington system colour-magnitude diagrams (CMDs) for 17
practically unstudied star clusters located in the bar as well as in
the inner disc and outer regions of the Large Magellanic Cloud (LMC).
Cluster sizes were estimated from star counts distributed throughout
the entire observed fields. Based on the best fits of theoretical
isochrones to the cleaned (C-T1, T1) CMDs, as well as on the
δT1 parameter and the standard giant branch method, we derive
ages and metallicities for the cluster sample. Four objects are found
to be intermediate-age clusters (1.8-2.5 Gyr), with [Fe/H] ranging
from -0.66 to -0.84. With the exception of SL 263, a very young cluster
(∼16 Myr), the remaining 12 objects are aged between 0.32 and 0.89 Gyr,
with their [Fe/H] values ranging from -0.19 to -0.50. We combined our
results with those for other 231 clusters studied in a similar way using
the Washington system. The resulting age-metallicity relationship shows
a significant dispersion in metallicities, whatever age is considered.
Although there seems to exist a clear tendency for the younger clusters
to be more metal rich than the intermediate ones, we believe that none
of the chemical evolution models currently available in the literature
reasonably well represents the recent chemical enrichment processes in
the LMC clusters. The present sample of 17 clusters is part of our ongoing
project of generating a data base of LMC clusters homogeneously studied
using the Washington photometric system and applying the same analysis
procedure.
Description:
We present results for 17 practically unstudied LMC star clusters,
8 of which (HS 409, BSDL 3060, HS 420, BSDL 3072, KMHK 1408, SL 736,
HS 424, and BSDL 3123) are projected on the bar. The remaining 9 clusters
(SL 48, KMHK 575, SL 263, BSDL 794, SL 490, LW 231, IC 2140, KMHK 1504,
and SL 775) are located in the inner disc and outer regions of the LMC
(Fig. 1).
Images for the selected sample were obtained on the nights of
2000 December 29-30, with the MOSAIC II camera of the Victor Blanco 4-m
telescope (scale 0.27 arcsec/pixel) at Cerro Tololo Inter-American
Observatory (CTIO), Chile.
Note that there is data only for nine clusters in the paper.
Objects:
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RA (ICRS) DE Designation(s)
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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
table1.dat 92 17 Observed star clusters in the LMC
table21.dat 60 22942 CT1 data of stars in the field of SL 48
table22.dat 60 55568 CT1 data of stars in the field of KMHK 575
table23.dat 60 55568 CT1 data of stars in the field of SL 263
table24.dat 60 62496 CT1 data of stars in the field of BSDL 794
table25.dat 60 14987 CT1 data of stars in the field of SL 490
table26.dat 60 12695 CT1 data of stars in the field of LW 231
table27.dat 60 13631 CT1 data of stars in the field of IC 2140
table28.dat 60 93961 CT1 data of stars in the field of HS 409
table29.dat 60 105855 CT1 data of stars in the field of BSDL 3060
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See also:
VII/183 : The Cluster System of the LMC (Kontizas+ 1990)
J/AcA/48/175 : OGLE SMC clusters (Pietrzynski+ 1998)
J/AcA/49/521 : OGLE LMC star clusters BVI photometry (Pietrzynski+, 1999)
J/AJ/117/238 : LMC extended catalog (Bica+, 1999)
J/MNRAS/389/678 : Cat. of extended objects in Magellanic Clouds (Bica+, 2008)
J/A+A/501/585 : CT1 photometry in five LMC star clusters (Piatti+, 2009)
J/A+A/555/A131 : Fundamental parameters of star clusters in the LMC
(Palma+, 2013)
J/A+A/586/A41 : LMC star clusters catalog (Palma+, 2016)
J/A+A/606/A21 : LMC bar star clusters (Piatti, 2017)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Cluster Star cluster name (1)
11- 34 A24 --- OName Other designation(s)
36- 37 I2 h RAh Hour of Right Ascension (J2000)
39- 40 I2 min RAm Minute of Right Ascension (J2000)
42- 43 I2 s RAs Second of Right Ascension (J2000)
45 A1 --- DE- Sign of the Declination (J2000)
46- 47 I2 deg DEd Degree of Declination (J2000)
49- 50 I2 arcmin DEm Arcminute of Declination (J2000)
52- 53 I2 arcsec DEs Arcsecond of Declination (J2000)
55- 61 F7.3 deg GLON [277.278/286.813] Galactic longitude
63- 69 F7.3 deg GLAT [-34.854/-30.189] Galactic latitude
71- 74 F4.2 arcmin r [0.19/1.15] Cluster radius from Bica et al.
(2008, J/MNRAS/389/678)
76- 79 F4.2 arcmin Rad1 [0.32/1.17] Cluster radius derived in the current
study in arcmin
81- 84 F4.1 pc Rad2 [4.6/17] Cluster radius derived in the current
study in parsecs
86- 92 A7 --- Table Table number for the corresponding stars data;
column added by CDS
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Note (1): Cluster identifications from:
SL = Shapley & Lindsay (1963IrAJ....6...74S 1963IrAJ....6...74S);
LW = Lynga & Westerlund (1963MNRAS.127...31L 1963MNRAS.127...31L);
KMHK = Kontizas et al. (1990, Cat. VII/183);
LOGLE = Pietrzynski et al. (1998, J/AcA/48/175; 1999, J/AcA/49/521);
BSDL = Bica et al. (1999, J/AJ/117/238);
HS = Hodge & Sexton (1966AJ.....71..363H 1966AJ.....71..363H).
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Byte-by-byte Description of file: table2[123456789].dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- Seq [2/105856] Sequential number within the field
8- 15 F8.3 pix Xpos [-0.474/2050.77] X position (1)
17- 24 F8.3 pix Ypos [-0.96/4098.5] Y position (1)
28- 33 F6.3 mag T1mag [14.543/24.652] T1 magnitude
38- 42 F5.3 mag e_T1mag [0.001/0.543] rms uncertainty on T1mag
46- 51 F6.3 mag C-T1 [-5.818/7.271] C-T1 colour index
56- 60 F5.3 mag e_C-T1 [0.003/0.754] rms uncertainty on C-T1
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Note (1): The dimension of each field region is 2048x4092 pixels.
1 pix=0.27 arcsec.
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History:
From electronic version of the journal
Acknowledgements:
Tali Palma: tpalma{at}astro.puc.cl
(End) Tiphaine Pouvreau [CDS] 22-Nov-2019