J/MNRAS/430/2358 SDSS photometry of LMC cluster SL 529 (Piatti, 2013)
A new extended main-sequence turnoff star cluster in the Large Magellanic Cloud.
Piatti A.E.
<Mon. Not. R. Astron. Soc., 430, 2358-2362 (2013)>
=2013MNRAS.430.2358P 2013MNRAS.430.2358P
ADC_Keywords: Magellanic Clouds ; Associations, stellar ; Photometry, SDSS
Keywords: techniques: photometric - galaxies: individual: LMC -
Magellanic Clouds - galaxies: star clusters: general
Abstract:
We present results on the age and metallicity estimates of the poorly
studied Large Magellanic Cloud (LMC) cluster SL 529, from CCD SDSS gr
photometry obtained at the Gemini South telescope with the GMOS
attached. The cluster main-sequence turnoffs (MSTO) region possesses
an extended structure, with an age spread (∼0.5Gyr) bigger than the
mean age width of known extended MSTO (EMSTO) LMC clusters. We report
for the first time a mean cluster age of 2.25Gyr and a mean cluster
metallicity of Z=0.004, which place it as the most metal-poor and
oldest cluster in the EMSTO LMC cluster group. In addition, the
cluster red clump appears to be formed by two concentrations of stars
- although it is not clear whether this feature can be caused, in
part, by binary interactions and mergers - whereas the cluster core
radius of 4.2pc is in excellent agreement with those determined for
the previously 12 known EMSTO LMC clusters.
Description:
Based on data obtained from the Gemini Science Archive, we collected
CCD SDSS gr (Fukugita et al., 1996AJ....111.1748F 1996AJ....111.1748F) images centred on
26 LMC clusters (GS-2010B-Q-74, PI: Pessev) along with observations of
standard fields and calibration frames (zero, sky-flat, dome-flat).
The data were obtained at the Gemini South telescope with the Gemini
Multi-Object Spectrograph (GMOS) attached (scale=0.146arcsec/pix).
The data consist in two exposures of 30s in g and two exposures of 15s
in r for each cluster under seeing conditions better than 0.6arcsec
and with airmass of 1.25-1.40. Nine Gemini Observatory standard
fields were observed along the five cluster observing nights, for
which two exposures of 5s per filter and airmass in the range
∼1.0-2.0 were obtained.
Objects:
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RA (2000) DE Designation(s)
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05 31 06 -63 32.4 SL 529 = [SL63] 529
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 50 5454 CCD SDSS gr data of stars in the field of SL 529
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ID Sequential number
6- 13 F8.3 pix Xpos X position (1)
15- 22 F8.3 pix Ypos Y position (1)
24- 29 F6.3 mag gmag SDSS g magnitude
31- 35 F5.3 mag e_gmag rms uncertainty on gmag
37- 42 F6.3 mag g-r SDSS g-r colour index
44- 48 F5.3 mag e_g-r rms uncertainty on g-r
50 I1 --- N Number of observations
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Note (1): Cluster centre : (Xc,Yc)=(1520±10,1100±10) pixels, for
position 05:31:06-63:32:23 (J2000). 1pix=0.146arcsec.
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Acknowledgements:
Andres Piatti, andres(at)oac.uncor.edu
(End) Patricia Vannier [CDS] 11-Apr-2014