J/MNRAS/463/1446 Star clusters in Magellanic Clouds (Nayak+, 2016)
Star clusters in the Magellanic Clouds.
I. Parameterisation and classification of 1072 clusters in the LMC.
Nayak P.K., Subramaniam A., Choudhury S., Indu G., Sagar R.
<Mon. Not. R. Astron. Soc., 463, 1446-1461 (2016)>
=2016MNRAS.463.1446N 2016MNRAS.463.1446N (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Associations, stellar ; Stars, ages
Keywords: Hertzsprung-Russell and colour-magnitude diagrams -
Magellanic Clouds - galaxies: star formation
Abstract:
We have introduced a semi-automated quantitative method to estimate
the age and reddening of 1072 star clusters in the Large Magellanic
Cloud (LMC) using the Optical Gravitational Lensing Experiment (OGLE)
III survey data. This study brings out 308 newly parameterised
clusters. In a first of its kind, the LMC clusters are classified into
groups based on richness/mass as very poor, poor, moderate and rich
clusters, similar to the classification scheme of open clusters in the
Galaxy. A major cluster formation episode is found to happen at
125±25Myr in the inner LMC. The bar region of the LMC appears
prominently in the age range 60-250Myr and is found to have a
relatively higher concentration of poor and moderate clusters. The
eastern and the western ends of the bar are found to form clusters
initially, which later propagates to the central part. We demonstrate
that there is a significant difference in the distribution of clusters
as a function of mass, using a movie based on the propagation (in
space and time) of cluster formation in various groups. The importance
of including the low mass clusters in the cluster formation history is
demonstrated. The catalog with parameters, classification, and cleaned
and isochrone fitted CMDs of 1072 clusters, which are available as
online material, can be further used to understand the hierarchical
formation of clusters in selected regions of the LMC.
Description:
In this study, we have identified star clusters of the Bica et al.
(2008, , Cat. J/MNRAS/389/678) catalogue in the OGLE III (Udalski et
al., 2008AcA....58...89U 2008AcA....58...89U) observed region and characterized them using
the V, I photometric data.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
catalog.dat 78 1072 A catalog is 1072 LMC star clusters are
presented here
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See also:
J/MNRAS/389/678 : Catalogue of extended objects in Magellanic Clouds
(Bica+, 2008)
Byte-by-byte Description of file: catalog.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Cluster name
13 I1 h RAh Central right ascension (J2000) (1)
15- 16 I2 min RAm Central right ascension (J2000) (1)
18- 19 I2 s RAs Central right ascension (J2000) (1)
21 A1 --- DE- Central declination sign (J2000 (1)
22- 23 I2 deg DEd Central declination (J2000 (1)
25- 26 I2 arcmin DEm Central declination (J2000 (1)
28- 29 I2 arcsec DEs Central declination (J2000 (1)
31- 34 F4.2 arcmin Radius Size of the cluster (1)
36- 39 F4.2 mag E(V-I) Estimated reddening
41- 44 F4.2 [yr] log(t) Estimated age
46- 49 F4.2 [yr] log(tG10) ?=- Glatt et al. (2010, Cat. J/A+A/517/A50)
estimation of age
51 A1 --- l_log(tPU00) Limit flag on log(tPU00)
52- 55 F4.2 [yr] log(tPU00) ? Pietrzynski & Udalski (2000,
Cat. J/AcA/50/337) estimation of age
56 A1 --- --- [,]
57- 60 F4.2 [yr] log(tPU00)2 ? Pietrzynski & Udalski (2000,
Cat. J/AcA/50/337) estimation of age
61- 64 F4.2 [yr] log(tPal16) ? Palma et al. (2016, Cat. J/A+A/586/A41)
earlier estimation of age
65 A1 --- --- [,]
66- 69 F4.2 [yr] log(tPal16)2 ? Palma et al. (2016, Cat. J/A+A/586/A41)
estimation of age
71- 74 F4.2 [yr] log(tP14) ? Piatti et al. (2014A&A...570A..74P 2014A&A...570A..74P or
2015, Cat. J/MNRAS/454/839) earlier
of age
76- 78 A3 --- Group Designated group number (I-V) of cluster
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Note (1): from Bica et al. (2008, Cat. J/MNRAS/389/678).
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-May-2018