J/A+A/647/A135 35 star clusters and fields in the SMC (Narloch+, 2021)
Metallicities and ages for 35 star clusters and their surrounding fields in
the Small Magellanic Cloud.
Narloch W., Pietrzynski G., Gieren W., Piatti A.E., Gorski M.,
Karczmarek P., Graczyk D., Suchomska K., Zgirski B., Wielgorski P.,
Pilecki B., Taormina M., Kaluszynski M., Pych W., Hajdu G., Rojas Garcia G.
<Astron. Astrophys. 647, A135 (2021)>
=2021A&A...647A.135N 2021A&A...647A.135N (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, photometry ; Photometry, uvby
Keywords: methods: observational - techniques: photometric -
galaxies: individual: Small Magellanic Cloud -
galaxies: star clusters: general - galaxies: abundances
Abstract:
In this work we study 35 stellar clusters in the Small Magellanic
Cloud (SMC) in order to provide their mean metallicities and ages. We
also provide mean metallicities of the fields surrounding the
clusters.
We used Stroemgren photometry obtained with the 4.1 m SOAR telescope
and take advantage of (b-y) and m1 colors for which there is a
metallicity calibration presented in the literature.
The spatial metallicity and age distributions of clusters across the
SMC are investigated using the results obtained by Stroemgren
photometry. We confirm earlier observations that younger, more
metal-rich star clusters are concentrated in the central regions of
the galaxy, while older, more metal-poor clusters are located farther
from the SMC center. We construct the age-metallicity relation for the
studied clusters and find good agreement with theoretical models of
chemical enrichment, and with other literature age and metallicity
values for those clusters. We also provide the mean metallicities for
old and young populations of the field stars surrounding the clusters,
and find the latter to be in good agreement with recent studies of the
SMC Cepheid population. Finally, the Stroemgren photometry obtained
for this study is made publicly available.
Description:
The catalog of the Stroemgren photometry for stars for which all three
Stroemgren vby filters were available and subsequently color indices
(b-y) and m1 could be calculated. Data were collected with 4.1-m SOAR
telescope placed in Cerro Pachon in Chile and equipped with the SOI
camera with field of view of 5.26'x5.26' and pixel scale of 0.154"/pix
during two runs: December 17-19, 2008 and January 16-18, 2009.
Photometric errors are presented in two columns, depending on the
method used for their evaluation: i) the DAOPHOT package or ii) full
error propagation of the transformation equations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 138 38 Star clusters in the SMC
table6.dat 169 224346 Photometric catalog
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/AJ/159/82 : Updated cat. of extended objects in Magellanic clouds
(Bica+, 2020)
J/A+A/602/A89 : Star clusters in the Magellanic Clouds (Perren+, 2017)
J/A+A/452/179 : Ages of SMC young clusters and field stars (Chiosi+, 2006)
J/A+A/517/A50 : Ages & luminosities of young SMC/LMC star clusters
(Glatt+, 2010)
J/A+A/616/A187 : SMC clusters age-dating & classification (Nayak+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- Cluster Name of the cluster
17- 18 I2 h RAh Cluster right ascension (J2000) from
Bica et al. (2020, Cat. J/AJ/159/82)
20- 21 I2 min RAm Cluster right ascension (J2000) from
Bica et al. (2020, Cat. J/AJ/159/82)
23- 26 F4.1 s RAs Cluster right ascension (J2000) from
Bica et al. (2020, Cat. J/AJ/159/82)
28 A1 --- DE- Declination sign (J2000) for epoch J2000 from
Bica et al. (2020, Cat. J/AJ/159/82)
29- 30 I2 deg DEd Declination (J2000) for epoch J2000 from
Bica et al. (2020, Cat. J/AJ/159/82)
32- 33 I2 arcmin DEm Declination (J2000) for epoch J2000 from
Bica et al. (2020, Cat. J/AJ/159/82)
35- 36 I2 arcsec DEs Declination (J2000) for epoch J2000 from
Bica et al. (2020, Cat. J/AJ/159/82)
38- 48 A11 "date" Date Date of observation
50- 52 I3 s Texpy Exposure time of filter y
54- 56 I3 s Texpb Exposure time of filter b
58- 60 I3 s Texpv Exposure time of filter v
62- 65 F4.2 --- Airmassy Airmass of observations in y band
67- 70 F4.2 --- Airmassb Airmass of observations in b band
72- 75 F4.2 --- Airmassv Airmass of observations in v band
77- 80 F4.2 arcsec Seeingy Average seeing in y band
82- 85 F4.2 arcsec Seeingb Average seeing in b band
87- 90 F4.2 arcsec Seeingv Average seeing in v band
92-138 A47 --- OName Other name(s) of the clusters in use
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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2- 10 F9.6 deg RAdeg Right ascension (J2000)
12- 21 F10.6 deg DEdeg Declination (J2000)
25- 32 F8.3 pix X x coordinate on the image
36- 43 F8.3 pix Y y coordinate on the image
46- 82 A37 --- Field Field containing a given cluster of stars
86- 91 F6.3 mag Vmag V magnitude
94- 98 F5.3 mag e_VmagDAO Photometric error of V magnitude resulting
from DAOPHOT
101-105 F5.3 mag e_Vmag Photometric error of V magnitude resulting
from full propagation of the transformation
equation to the standard system
109-114 F6.3 mag (b-y) (b-y) color index
117-121 F5.3 mag e_(b-y)DAO Photometric error of (b-y) color resulting
from DAOPHOT
124-128 F5.3 mag e_(b-y) Photometric error of (b-y) color resulting
from full propagation of the transformation
equation to the standard system
132-137 F6.3 mag m1 m1 color index
139-144 F6.3 mag e_m1DAO Photometric error of m1 index resulting
from DAOPHOT
146-151 F6.3 mag e_m1 Photometric error of m1 index resulting
from full propagation of the transformation
equation to the standard system
156-160 F5.3 --- CHI CHI parameter from DAOPHOT
163-169 F7.3 --- SHARP SHARP parameter from DAOPHOT
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Acknowledgements:
Weronika Narloch, wnarloch(at)astro-udec.cl
(End) Patricia Vannier [CDS] 15-Mar-2021