J/MNRAS/507/3312 Properties of SMC star clusters (Gatto+, 2021)
STEP survey. II. Structural analysis of 170 star clusters in the SMC.
Gatto M., Ripepi V., Bellazzini M., Tosi M., Cignoni M., Tortora C.,
Leccia S., Clementini G., Grebel E.K., Longo G., Marconi M., Musella I.
<Mon. Not. R. Astron. Soc., 507, 3312-3330 (2021)>
=2021MNRAS.507.3312G 2021MNRAS.507.3312G (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Clusters, open ; Optical
Keywords: surveys - Hertzsprung-Russsel and colour-magnitude diagrams -
galaxies: star clusters: general - Magellanic Clouds
Abstract:
We derived surface brightness profiles in the g band for 170 Small
Magellanic Cloud (SMC) star clusters (SCs) mainly located in the
central region of the galaxy. We provide a set of homogeneous
structural parameters obtained by fitting Elson-Fall-Freeman and
King models. Through a careful analysis of their colour-magnitude
diagrams we also supply the ages for a subsample of 134 SCs. For the
first time, such a large sample of SCs in the SMC is homogeneously
characterized in terms of their sizes, luminosities, and masses,
widening the probed region of the parameter space, down to hundreds of
solar masses. We used these data to explore the evolution of the
SC's structural parameters with time. In particular, we confirm the
existence of a physical mechanism that induces an increase of the core
radius after 0.3-1.0Gyr. We suggest that cluster mass could be the
main parameter driving the inner expansion, as none of the SCs having
log(M/M-☉_)≤3.5dex analysed in this work undergoes to such an
expansion. We also detected a mass-size relationship almost over the
entire range of SCs masses investigated here. Finally, our data
suggest that globally the SMC SC system is dynamically evolved.
Description:
The data used in this work were obtained with the VLT Survey Telescope
(VST) The telescope is equipped with OmegaCAM, a camera with a
field-of-view of 1x1 deg2. The camera is a mosaic of 32-CCD,
16000x16000 detectors with a pixel scale of 0.214 arcsec/pix.
For each of the 170 SCs we report, if available: their name,
equatorial coordinates, core radii and solar luminosities derived with
EFF profile, core radii, concentration, half-light radii and solar
luminosities derived with the King profile, their ages, reddening and
masses, the mass-to-light ratio, their relaxation time and the tile
where the SC in question resides.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
clusters.dat 154 170 Cluster properties (table 1)
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Byte-by-byte Description of file: clusters.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Cluster name
9- 15 F7.4 deg RAdeg Right ascension (J2000.0)
17- 24 F8.4 deg DEdeg Declination (J2000.0)
26- 30 F5.2 pc rceff ?=99.99 Cluster core radius derived
with EFF profile
32- 36 F5.2 pc e_rceff ?=99.99 Uncertainties on the core radius
38- 42 F5.2 [Lsun] logLeff ?=99.99 Cluster luminosity derived with
EFF profile
44- 48 F5.2 [Lsun] e_logLeff ?=99.99 Uncertainties on the total luminosity
50- 54 F5.2 pc rck Cluster core radius derived with King profile
56- 60 F5.2 pc e_rck Uncertainties on the core radius
62- 66 F5.2 --- c Concentration of the cluster
68- 72 F5.2 --- e_c Uncertainties on the concentration
74- 78 F5.2 pc rh Cluster half-light radius
80- 84 F5.2 pc e_rh Uncertainties on the half-light radius
86- 90 F5.2 [Lsun] logLk Cluster luminosity derived with King profile
92- 96 F5.2 [Lsun] e_logLk Uncertainties on the total luminosity
98-102 F5.2 [yr] logt ?=99.99 Cluster Age in logarithmic scale
104-108 F5.2 [yr] b_logt ?=99.99 Inferior limit of the cluster age
110-114 F5.2 [yr] B_logt ?=99.99 Superior limit of the cluster age
116-120 F5.2 mag E(B-V) ?=99.99 Cluster reddening
122-126 F5.2 [Msun] logMass ?=99.99 Cluster mass
128-132 F5.2 [Msun] b_logMass ?=99.99 Inferior limit of the mass
134-138 F5.2 [Msun] B_logMass ?=99.99 Superior limit of the mass
140-144 F5.2 [-] log(M/L) ?=99.99 Mass-to-light ratio in
logarithmic scale
146-150 F5.2 [yr] log(trh) ?=99.99 Relaxation time in logarithmic scale
152-154 A3 --- Tile Tile where the SC resides
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Acknowledgements:
Massimiliano Gatto, massimiliano.gatto(at)inaf.it
References:
Ripepi et al., Paper I 2014MNRAS.442.1897R 2014MNRAS.442.1897R
(End) Massimiliano Gatto [INAF, Italy], Patricia Vannier [CDS] 15-Sep-2022