J/A+A/440/111 Spectra of SMC star clusters (Piatti+, 2005)
Integrated spectral analysis of 18 concentrated star clusters in the
Small Magellanic Cloud.
Piatti A.E., Santos J.F.C.Jr, Claria J.J., Bica E., Ahumada A.V.,
Parisi M.C.
<Astron. Astrophys. 440, 111 (2005)>
=2005A&A...440..111P 2005A&A...440..111P
ADC_Keywords: Magellanic Clouds ; Associations, stellar ; Spectroscopy
Keywords: galaxies: star clusters - techniques: spectroscopic -
Magellanic Clouds
Abstract:
We present flux-calibrated integrated spectra in the range 360-680nm
for 18 concentrated SMC clusters. The objects are part of a systematic
spectroscopic survey of SMC star clusters which is being undertaken at
Complejo Astronomico El Leoncito (CASLEO) in San Juan (Argentina) and
Cerro Tololo Inter-American Observatory (CTIO, Chile).
Description:
The observations were carried out with the CASLEO 2.15m telescope
during four nights in November 2001 and five nights in October 2002
and with the CTIO 1.5 m telescope during four nights in September
2003. In all the CASLEO runs we employed a CCD camera containing a
Tektroniks chip of 1024x1024 pixels attached to a REOSC spectrograph
(simple mode), the size of each pixel being 24µmx24µm; one pixel
corresponds to 0.94arcsec on the sky. The slit was set in the
East-West direction and the observations were performed by scanning
the slit across the objects in the North-South direction in order to
get a proper sampling of cluster stars. The long slit corresponding to
4.7arcmin on the sky, allowed us to sample regions of the background
sky. We used a grating of 300 grooves/mm, producing an average
dispersion in the observed region of ∼140Å/mm (3.46Å/pixel). The
spectral coverage was ∼3600-6800Å. The slit width was 4.2arcsec,
providing a resolution [full width at half-maximum (FWHM)] of ∼14Å,
as deduced from the comparison lamp lines. For the CTIO observations,
we used a CCD Loral 1K chip of 1200x800 pixels (pixel diameter =
15µm), controlled by the CTIO ARCON3.9 data acquisition system at a
gain of 2.05e-ADU-1 with a readout noise of 7.4e-ADU-1. The
same slit width of 4.2arcsec as in CASLEO was used at CTIO, thus
providing a resolution of about 11Å. We applied to the cluster
spectra extinction corrections and flux calibrations derived from the
observed standard stars. The spectra presented here are not corrected
for interstellar extinction and their fluxes (J/s/m^+2/nm) are
normalized to 1 at 5870Å. Cluster information is in the table
clusters.dat.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
clusters.dat 86 18 List of clusters
spec/* . 18 Individual spectra
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See also:
J/AJ/116/2395 : BV photometry in five SMC clusters (Mighell+, 1998)
Byte-by-byte Description of file: clusters.dat
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Bytes Format Units Label Explanations
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1- 41 A41 --- Cluster Name of star cluster
43 I1 h RAh Right ascension (J2000)
45- 46 I2 min RAm Right ascension (J2000)
48- 49 I2 s RAs Right ascension (J2000)
51 A1 --- DE- Declination sign (J2000)
52- 53 I2 deg DEd Declination (J2000)
55- 56 I2 arcmin DEm Declination (J2000)
58- 59 I2 arcsec DEs Declination (J2000)
61- 64 F4.2 arcmin Diam Diameter
66- 71 A6 --- Obs Observatory
73- 75 I3 --- S/N Signal to noise
77- 86 A10 --- Spectra Name of the file containing the spectrum,
in subdirectory spec
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Byte-by-byte Description of file: spec/*
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Bytes Format Units Label Explanations
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1- 6 F6.1 0.1nm lambda Central wavelength for each pixel
11- 19 E9.3 W/m2/nm Flux ? Normalized flux
20 A1 --- n_Flux [*] *: no measured flux
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Acknowledgements:
J. Santos, jsantos(at)fisica.ufmg.br
(End) Patricia Vannier [CDS] 30-May-2005