***************************************************** *** CFHTLS-T04 photometric redshifts version 1.4 **** ***************************************************** April 22nd , 2010 README file for the CFHTLS T0004 deep photometric redshift catalogues. See Coupon et al. (2009) for details. This release includes 4 fields in the deep part of the survey (1deg2 each) ========================================================================== ============ CATALOGUE HEADER for zphot catalogues ========================================================================== 1:'ID_TERAPIX_T04'. Object id from T0004 Terapix catalogues. 2:'x' pixel coordinate 3:'y' pixel coordinate 4:'alpha' (J2000) coordinate in degrees. 5:'delta' (J2000) coordinate in degrees. 6:'zp_reliable' gives a reliable estimate on the redshift: is 'zp_first' (galaxy) if 'Nbands'=5 AND 'chi2_gal' < 1000 AND 'flag_terapix' < 2 AND 'object'=0, or 0 (star) if 'Nbands'=5 AND 'chi2_gal' < 1000 AND 'flag_terapix' < 2 AND 'object'=1, or -99, otherwise. CAUTION: redshifts in the Wide field are reliable for i'AB < 22.5 and in the Deep field for i'AB < 24. 7:'1_sigma_error' = ('zp_left_68' - 'zp_right_68')/2 CAUTION: not accurate in case of a second solution. 8:'zp_left_68'. Low redshift at 68% confidence interval (Discrete values with interval = 0.04). 9:'zp_right_68'. High redshift at 68% confidence interval (Discrete values with interval = 0.04). 10:'gal_template'. Best fit galaxy templates: 1 - 21: CWW El 22 - 37: CWW Sbc 38 - 48: CWW Scd 49 - 58: CWW Im 59 - 62: Kinney et al Starburst 1 and 2. 11:'reddening'. Estimated galaxy internal extinction from 0 to 0.2, for Scd and later types only. 12:'zp_first'. Maximum likelihood estimate of the redshift. 13:'zp_second'. Second redshift solution if a second peak is found (larger than 5% of the first peak height), -99 otherwise. 14:'zp_QSO'. Redshift solution from the QSO library. WARNING: this estimate has NOT been tested. 15:'object'. Estimated nature of the object using both rh and photometric information. 0: galaxy, 1:star. - i'AB < 21: star if rh < rhlimit, galaxy otherwise - 21 < i'AB < 23: star if rh < rhlimit AND chi2_star < 2*chi2_gal, galaxy otherwise - i'AB > 23: galaxy. 16:'flag_terapix'. Photometric flag given in Terapix catalogues. Star/galaxy separation based on rh and i'AB only. 0:galaxy ; 1:star ; >1: masked. 17,18,19:'chi2_gal', 'chi2_star' and 'chi2_QSO'. (Not reduced) chi2's from the galaxy template library, the star template library and the QSO template library, respectively. 20:'chi2_gal_second'. (Not reduced) chi2 for the second redshift solution from the galaxy template library 21:'Nbands'. Number of bands used for the redshift computation (from 1 to 5). less than 3 is problematic. 22:'rh'. Half light radius (also called r2). 23:'EB_V'. Galactic extinction from Schlegel et al. dust map. 24-33: Magnitudes + error. Magnitudes are corrected from the galactic extinction and 0.2 u-offsets. SExtractor errors are multiplied by 1.5 to account for the pixel noise correlation. 34-38: Estimated absolute magnitudes in the u,g,r,i and z bands ========================================================================== ============ CATALOGUE HEADER FOR PDFz catalogues ========================================================================== The maximum of the PDFz has been set at 1 (then the PDFz are not normalized). The PDFz is computed at the following redshifts: 0.00 0.04 0.08 0.12 0.16 0.20 0.24 0.28 0.32 0.36 0.40 0.44 0.48 0.52 0.56 0.60 0.64 0.68 0.72 0.76 0.80 0.84 0.88 0.92 0.96 1.00 1.04 1.08 1.12 1.16 1.20 1.24 1.28 1.32 1.36 1.40 1.44 1.48 1.52 1.56 1.60 1.64 1.68 1.72 1.76 1.80 1.84 1.88 1.92 1.96 2.00 2.04 2.08 2.12 2.16 2.20 2.24 2.28 2.32 2.36 2.40 2.44 2.48 2.52 2.56 2.60 2.64 2.68 2.72 2.76 2.80 2.84 2.88 2.92 2.96 3.00 3.04 3.08 3.12 3.16 3.20 3.24 3.28 3.32 3.36 3.40 3.44 3.48 3.52 3.56 3.60 3.64 3.68 3.72 3.76 3.80 3.84 3.88 3.92 3.96 4.00 4.04 4.08 4.12 4.16 4.20 4.24 4.28 4.32 4.36 4.40 4.44 4.48 4.52 4.56 4.60 4.640 4.68 4.72 4.76 4.80 4.84 4.88 4.92 4.96 5.00 5.04 5.08 5.12 5.16 5.20 5.24 5.28 5.32 5.36 5.40 5.44 5.48 5.52 5.56 5.60 5.64 5.68 5.72 5.76 5.80 5.84 5.88 5.92 5.96 6.000 The format is Id PDFz(0) PDFz(0.04) ............. PDFz(6.0)