J/MNRAS/444/1425 gi photometry of 14 LMC star clusters (Piatti+, 2014)
Gemini/GMOS photometry of intermediate-age star clusters in the
Large Magellanic Cloud.
Piatti A.E., Keller S.C., Mackey A.D., Da Costa G.S.
<Mon. Not. R. Astron. Soc., 444, 1425-1441 (2014)>
=2014MNRAS.444.1425P 2014MNRAS.444.1425P
ADC_Keywords: Magellanic Clouds ; Associations, stellar ; Photometry, SDSS
Keywords: techniques: photometric - galaxies: individual: LMC -
Magellanic Clouds
Abstract:
We present Gemini South GMOS g, i photometry of 14 intermediate-age
Large Magellanic Cloud (LMC) star clusters, namely: NGC 2155, 2161,
2162, 2173, 2203, 2209, 2213, 2231, 2249, Hodge 6, SL 244, 505, 674,
and 769, as part of a continuing project to investigate the extended
main-sequence turn-off (EMSTO) phenomenon. Extensive artificial star
tests were made over the observed field of view. These tests reveal
the observed behaviour of photometric errors with magnitude and
crowding. The cluster stellar density radial profiles were traced from
star counts over the extent of the observed field. We adopt cluster
radii and build colour-magnitude diagrams (CMDs) with cluster features
clearly identified. We used the cluster (g, g-i) CMDs to estimate ages
from the matching of theoretical isochrones. The studied LMC clusters
are confirmed to be intermediate-age clusters, which range in age
9.10<log(t)<9.60. NGC 2162 and NGC 2249 look like new EMSTO
candidates, in addition to NGC 2209, on the basis of having dual red
clumps.
Description:
We obtained images of 14 candidate LMC intermediate-age clusters with
the Gemini South telescope and the GMOS-S instrument through g and i
filters. In imaging mode, GMOS-S has a field of view of approximately
5.5-arcminx5.5-arcmin at a scale of 0.146arcsec per (2x2 binned)
pixel. The detector is a 3x1 mosaic of 2Kx4K EEV CCDs. Observations
were executed in queue mode (under programmes GS-2011A-Q-43,
GS-2012A-Q-15, and GS-2013A-Q-17) which enabled the data to be
obtained in excellent seeing (0.35-0.78-arcsec FWHM) and under
photometric conditions.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 103 14 Observation log of selected clusters
table2.dat 60 15106 CCD gi data of stars in the field of NGC 2155
table3.dat 60 11747 CCD gi data of stars in the field of NGC 2161
table4.dat 60 6184 CCD gi data of stars in the field of NGC 2162
table5.dat 60 14839 CCD gi data of stars in the field of NGC 2173
table6.dat 60 7798 CCD gi data of stars in the field of NGC 2203
table7.dat 60 7347 CCD gi data of stars in the field of NGC 2209
table8.dat 60 10178 CCD gi data of stars in the field of NGC 2213
table9.dat 60 6666 CCD gi data of stars in the field of NGC 2231
table10.dat 60 8924 CCD gi data of stars in the field of NGC 2249
table11.dat 60 63932 CCD gi data of stars in the field of Hodge 6
table12.dat 60 34261 CCD gi data of stars in the field of SL 244
table13.dat 60 24329 CCD gi data of stars in the field of SL 505
table14.dat 60 11294 CCD gi data of stars in the field of SL 674
table15.dat 60 16303 CCD gi data of stars in the field of SL 769
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Cluster Star cluster name
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 17 I2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 27 I2 arcsec DEs Declination (J2000)
29- 40 A12 s Exp.g Time exposures in g-band (times x s)
42- 45 F4.2 --- AM.g1 [1.2/1.6] Airmass in g band (min)
46 A1 --- --- [-]
47- 50 F4.2 --- AM.g2 [1.2/1.6]? Airmass in g band (max)
52- 55 F4.2 arcsec See.g1 [0.3/0.8] Seeing in g band (min)
56 A1 --- --- [-]
57- 60 F4.2 arcsec See.g2 [0.3/0.8] Seeing in g band (max)
62- 71 A10 s Exp.i Time exposures in i-band (times x s)
73- 76 F4.2 --- AM.i1 [1.2/1.6] Airmass in i band (min)
77 A1 --- --- [-]
78- 81 F4.2 --- AM.i2 [1.2/1.7]? Airmass in i band (max)
83- 86 F4.2 arcsec See.i1 [0.3/0.8] Seeing in i band (min)
87 A1 --- --- [-]
88- 91 F4.2 arcsec See.i2 [0.3/0.8] Seeing in i band (max)
93-103 A11 --- FileName Name of the table with photometry
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table[23456789].dat table1?.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- Seq [1/63932] Star sequential number within cluster
7- 8 I2 h RAh Star right ascension (J2000)
10- 11 I2 min RAm Star right ascension (J2000)
13- 18 F6.3 s RAs Star right ascension (J2000)
20 A1 --- DE- Declination sign (J2000)
21- 22 I2 deg DEd Declination (J2000)
24- 25 I2 arcmin DEm Declination (J2000)
27- 31 F5.2 arcsec DEs Declination (J2000)
33- 38 F6.3 mag gmag GMOS g magnitude
40- 44 F5.3 mag e_gmag rms uncertainty on gmag
46- 51 F6.3 mag g-i GMOS g-i colour index
53- 57 F5.3 mag e_g-i rms uncertainty in g-i
59- 60 I2 --- o_Seq [1/14] Number of observations
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Apr-2015