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J/ApJS/184/218     The zCOSMOS 10k-bright spectroscopic sample    (Lilly+, 2009)

The zCOSMOS 10k-Bright spectroscopic sample. Lilly S.J., Le Brun V., Maier C., Mainieri V., Mignoli M., Scodeggio M., Zamorani G., Carollo M., Contini T., Kneib J.-P., Le Fevre O., Renzini A., Bardelli S., Bolzonella M., Bongiorno A., Caputi K., Coppa G., Cucciati O., De La Torre S., De Ravel L., Franzetti P., Garilli B., Iovino A., Kampczyk P., Kovac K., Knobel C., Lamareille F., Le Borgne J.-F., Pello R., Peng Y., Perez-Montero E., Ricciardelli E., Silverman J.D., Tanaka M., Tasca L., Tresse L., Vergani D., Zucca E., Ilbert O., Salvato M., Oesch P., Abbas U., Bottini D., Capak P., Cappi A., Cassata P., Cimatti A., Elvis M., Fumana M., Guzzo L., Hasinger G., Koekemoer A., Leauthaud A., Maccagni D., Marinoni C., McCracken H., Memeo P., Meneux B., Porciani C., Pozzetti L., Sanders D., Scaramella R., Scarlata C., Scoville N., Shopbell P., Taniguchi Y. <Astrophys. J. Suppl. Ser., 184, 218-229 (2009)> =2009ApJS..184..218L
ADC_Keywords: Redshifts ; Galaxies, optical ; Magnitudes ; Active gal. nuclei Surveys Keywords: cosmology: observations - galaxies: active - galaxies: distances and redshifts - galaxies: evolution - large-scale structure of universe - quasars: general - surveys Abstract: We present spectroscopic redshifts of a large sample of galaxies with IAB<22.5 in the COSMOS field, measured from spectra of 10644 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 10109 objects. The average accuracy of individual redshifts is 110km/s, 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. Description: Observations for the 10k sample were carried out with the VIMOS spectrograph mounted on the 8m VLT/UT3 telescope during extensive Service Mode runs in 2005 and 2006. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table3.dat 47 10644 zCOSMOS-bright 10k sample
See also: J/ApJS/172/70 : zCOSMOS-bright catalog (Lilly+, 2007) J/A+A/510/A56 : zCOSMOS type-2 AGN (Bongiorno, 2010) Byte-by-byte Description of file: table3.dat
Bytes Format Units Label Explanations
1- 6 I6 --- zCOSMOS zCOSMOS identification number 8- 17 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000) 19- 26 F8.6 deg DEdeg Declination in decimal degrees (J2000) 28- 33 F6.4 --- z ?=9.9999 Spectroscopic redshift 35- 39 F5.1 --- CClass Confidence class indicating reliability (1) 41- 45 F5.2 mag Imag HST F814W filter selection AB magnitude 47 I1 --- Mask Mask priority flag (2)
Note (1): The Confidence Class is made of a number and a decimal modifier. * Confidence number: 4 = a very secure redshift with an exhibition-quality spectrum 3 = a very secure redshift 2 = a likely redshift about which there is some doubt 9 = a securely detected line which is believed to be either [OII]3727 or Hα6563 1 = an insecure redshift 0 = no redshift measurement attempted 10 = as above but for broad line AGN; with 18 instead of 9, reflecting the greater range of possibilities 20 = As above but for a target only observed as a secondary target in a slit centered on another object 200 = 20 * Decimal place modifiers: .5 = The spectroscopic and photometric redshifts are consistent to within 0.08(1+z) .4 = No photometric redshift is available for some reason .3 = For Class 9 and 18 one-line redshifts only, the spectroscopic redshift is consistent only after the spectroscopic redshift is changed to the alternate redshift .1 = The spectroscopic and photometric redshifts differ by more than 0.08(1+z) The set of objects defined as Classes 1.5, 2.4, 2.5, 9.3, 9.5 and all Class 3.x and 4.x comprise 88% of the sample (95% between 0.5<z<0.8) and are estimated to be 99% reliable. The redshifts with Classes 1.1, 2.1 and 9.1 (and 21.1, 22.1 and 29.1) are likely to be incorrect and should not be used, even though they are retained in the catalogue for completeness. See section 2.2.2 for further explanation. Note (2): The mask priority indicates the priority for insertion in the slit masks as follows: 1 = a randomly selected object from the main catalog 2 = a "compulsory target" that has a roughly twice higher chance of having been observed 0 = an object that was not intended to be observed (e.g. because it was thought to be a star) but in fact was observed, usually as a secondary object in the slit of another target.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 15-Feb-2010
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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