J/A+A/392/395 Ks-band magnitudes of the K20 sample (Cimatti+, 2002)
The K20 survey. III. Photometric and spectroscopic properties of the sample.
Cimatti A., Mignoli M., Daddi E., Pozzetti L., Fontana A., Saracco P.,
Poli F., Renzini A., Zamorani G., Broadhurst T., Cristiani S., D'Odorico S.,
Giallongo E., Gilmozzi R., Menci N.
<Astron. Astrophys. 392, 395 (2002)>
=2002A&A...392..395C 2002A&A...392..395C
ADC_Keywords: Galaxies, photometry ; Photometry, infrared
Keywords: galaxies: fundamental parameters - galaxies: photometry -
galaxies: distances and redshifts
Abstract:
The K20 survey is an ESO VLT optical and near-infrared spectroscopic
survey aimed at obtaining spectral information and redshifts of a
complete sample of about 550 objects to Ks≤20.0 over two
independent fields with a total area of 52arcmin2. In this paper we
discuss the scientific motivation of such a survey, we describe the
photometric and spectroscopic properties of the sample, and we release
the Ks-band photometric catalog. Extensive simulations showed that
the sample is photometrically highly complete to Ks=20. The observed
galaxy counts and the R-Ks color distribution are consistent with
literature results.
We observed spectroscopically 94% of the sample, reaching a
spectroscopic redshift identification completeness of 92% to
Ks≤20.0 for the observed targets, and of 87% for the whole sample
(i.e. counting also the unobserved targets). Deep spectroscopy was
complemented with multi-band deep imaging in order to derive tested
and reliable photometric redshifts for the galaxies lacking of
spectroscopic redshifts. The results show a very good agreement
between the spectroscopic and the photometric redshifts with
<z(spe)-z(phot)≥0.01 and with a dispersion of
σ(Δz)=0.09. Using both the spectroscopic and the
photometric redshifts, we reached an overall redshift completeness of
about 98%. The size of the sample, the redshift completeness, the
availability of high quality photometric redshifts and multicolor
spectral energy distributions make the K20 survey database one of the
most complete samples available to date for constraining the currently
competing scenarios of galaxy formation and for a variety of other
galaxy evolution studies.
Description:
Ks-band "total" magnitudes of the K20 sample galaxies. For each
galaxy, the ID name, equatorial coordinates (J2000), total magnitudes
and magnitude errors (1σ) are given. A magnitude error equal to
0.30 magnitudes means that the object was deblended. The magnitudes
are not corrected for Galactic extinction. According to the maps of
Schlegel et al. (1998ApJ...500..525S 1998ApJ...500..525S), the extinction are
AK=0.007mag and AK=0.003mag in the 0055-269 and in the CDFS fields
respectively. The coordinates given in these tables were obtained by
applying rigid offsets using USNO stars present in the fields, but no
corrections for distorsions were applied because of the small number
of suitable stars in each field. Thus, the precision of such
coordinates is about ±0.4" both in RA and in Dec, yielding a total
uncertainty in the position of about 0.6" (1σ).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
0055k.dat 46 198 Positions and magnitudes in the 0055-269 field
cdfsk.dat 46 348 Positions and magnitudes in the CDFS
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Byte-by-byte Description of file: 0055k.dat cdfsk.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- ID Object identification number
12 I1 h RAh Right ascension (J2000.0)
14- 15 I2 min RAm Right ascension (J2000.0)
17- 21 F5.2 s RAs Right ascension (J2000.0)
23 A1 --- DE- Declination sign (J2000.0)
24- 25 I2 deg DEd Declination (J2000.0)
27- 28 I2 arcmin DEm Declination (J2000.0)
30- 34 F5.2 arcsec DEs Declination (J2000.0)
36- 40 F5.2 mag Ks Ks-band total magnitude
42- 45 F4.2 mag e_Ks Ks-band total magnitude 1sigma error
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Acknowledgements: Andrea Cimatti
References:
Cimatti et al., Paper I 2002A&A...381L..68C 2002A&A...381L..68C
Daddi et al., Paper II 2002A&A...384L...1D 2002A&A...384L...1D
Cimatti et al., Paper IV 2002A&A...391L...1C 2002A&A...391L...1C
(End) Andrea Cimatti [INAF-Arcetri, Italy] 04-Jun-2002