J/MNRAS/489/5087 Photometry of stars in SMC's central bar (Strantzalis+, 2019)
Discrete star formation events in the central bar of the Small Magellanic Cloud.
Strantzalis A., Hatzidimitriou D., Zezas A., Antoniou V., Lianou S.,
Tsilia S.
<Mon. Not. R. Astron. Soc., 489, 5087-5097 (2019)>
=2019MNRAS.489.5087S 2019MNRAS.489.5087S (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Galaxies, photometry ; Optical
Keywords: techniques: photometric - galaxies: evolution - Magellanic Clouds -
galaxies: photometry - galaxies: star formation
Abstract:
We present the results of the photometric analysis of a large part of
the main body of the Small Magellanic Cloud. Using the 6.5m Magellan
Telescope at the Las Campanas Observatory in Chile, we have acquired
deep B and I images in four fields (0.44deg each in diameter),
yielding accurate photometry for 1068893 stars down to 24th magnitude,
with a spatial resolution of 0.20arcsec per pixel. Colour-magnitude
diagrams and (completeness-corrected) luminosity functions have been
constructed, yielding significant new results that indicate at least
two discrete star formation events over a period from 2.7 to 4Gyr ago.
Also, we have derived star formation rates as a function of look-back
time and have found enhancements of SF between 4 and 6Gyr and at
younger ages.
Description:
Observations of four fields in the SMC were obtained with the 6.5m
Magellan Telescope at the Las Campanas Observatory in Chile on 2004
October 4, using the Inamori Magellan Areal Camera and Spectrograph
(IMACS; Dressler et al. 2011PASP..123..288D 2011PASP..123..288D). IMACS is a wide-field
imager and multi-object spectrograph with an eight CCD mosaic. In its
f/2 configuration, it provides a 0.44deg diameter field of view with
0.2arcsec pixel size. The images were taken through B and I standard
Johnson-Cousins filters. Each exposure was 120s long in B and 30s in
I. Each image was constructed from a total of six dithered single
exposures in B and two in I.
The images were bias subtracted and flat fielded using the
IRAF/CCDPROC tool (Tody 1993ASPC...52..173T 1993ASPC...52..173T). Astrometry was achieved
using the 2-Micron All-Sky Survey (2MASS; Skrutskie et al.
2006AJ....131.1163S 2006AJ....131.1163S, Cat. VII/233) catalogue as reference.
Table 3 provides the results of the photometry for a total of 1068803
sources in four SMC fields located along the bar of the SMC.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 120 1068803 Catalogue of detected sources
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1 I1 --- Field [3/6] Field number
3 I1 --- CCD [1/8] CCD number within the specified field
5- 11 I7 --- ID [1/1068803] Unique source identifier
13- 25 F13.10 deg RAdeg Right ascension (J2000)
27- 40 F14.10 deg DEdeg Declination (J2000)
42- 59 F18.15 mag Bmag Johnson-Cousins B-band magnitude
61- 80 F20.18 mag e_Bmag Error on Bmag
82- 99 F18.15 mag Imag Johnson-Cousins I-band magnitude
101-120 F20.18 mag e_Imag Error on Imag
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 19-Jan-2023