THE zCOSMOS 10k-BRIGHT SPECTROSCOPIC SAMPLE

Journal Article · Thu Oct 01 00:00:00 EDT 2009 · Astrophysical Journal, Supplement Series

DOI:https://doi.org/10.1088/0067-0049/184/2/218; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21301583

Lilly, Simon J; Maier, Christian; Carollo, Marcella; Caputi, Karina ^[1]; Le Brun, Vincent; Kneib, Jean-Paul; Le Fevre, Olivier; De la Torre, Sylvain; De Ravel, Loic ^[2]; Mainieri, Vincenzo ^[3]; Mignoli, Marco; Zamorani, Gianni; Bardelli, Sandro; Bolzonella, Micol; Coppa, Graziano ^[4]; Scodeggio, Marco ^[5]; Contini, Thierry ^[6]; Renzini, Alvio ^[7]; Bongiorno, Angela ^[8]; Cucciati, Olga ^[9]

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1. Institute for Astronomy, ETH Zurich, Wolfgang-Pauli-strasse 27, 8093 Zurich (Switzerland)
2. Laboratoire d'Astrophysique de Marseille, 38, rue Frederic Joliot-Curie, 13388 Marseille Cedex 13 (France)
3. European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching (Germany)
4. INAF Osservatorio Astronomico di Bologna, Via Ranzani 1, 40127 Bologna (Italy)
5. INAF - IASF Milano, Via E. Bassini 15, 20133 Milano (Italy)
6. Laboratoire d'Astrophysique de Toulouse/Tarbes, Universite de Toulouse, 14 avenue Edouard Belin, 31400 Toulouse (France)
7. Dipartimento di Astronomia, Universita di Padova, Vicolo dell'Osservatorio 5, 35122 Padova (Italy)
8. Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, 85748 Garching (Germany)
9. INAF Osservatorio Astronomico di Brera, via Brera 28, 20121 Milano (Italy)

We present spectroscopic redshifts of a large sample of galaxies with I {sub AB} < 22.5 in the COSMOS field, measured from spectra of 10,644 objects that have been obtained in the first two years of observations in the zCOSMOS-bright redshift survey. These include a statistically complete subset of 10,109 objects. The average accuracy of individual redshifts is 110 km s{sup -1}, independent of redshift. The reliability of individual redshifts is described by a Confidence Class that has been empirically calibrated through repeat spectroscopic observations of over 600 galaxies. There is very good agreement between spectroscopic and photometric redshifts for the most secure Confidence Classes. For the less secure Confidence Classes, there is a good correspondence between the fraction of objects with a consistent photometric redshift and the spectroscopic repeatability, suggesting that the photometric redshifts can be used to indicate which of the less secure spectroscopic redshifts are likely right and which are probably wrong, and to give an indication of the nature of objects for which we failed to determine a redshift. Using this approach, we can construct a spectroscopic sample that is 99% reliable and which is 88% complete in the sample as a whole, and 95% complete in the redshift range 0.5 < z < 0.8. The luminosity and mass completeness levels of the zCOSMOS-bright sample of galaxies is also discussed.

• OSTI ID: 21301583
• Journal Information: Astrophysical Journal, Supplement Series, Vol. 184, Issue 2; Other Information: DOI: 10.1088/0067-0049/184/2/218; Country of input: International Atomic Energy Agency (IAEA); ISSN 0067-0049
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ACCURACY
COSMOLOGY
DISTANCE
GALACTIC EVOLUTION
GALAXIES
LUMINOSITY
MASS
QUASARS
RED SHIFT
UNIVERSE