VII/259 6dF galaxy survey final redshift release (Jones+, 2009) ================================================================================ 6dF galaxy survey final redshift release Jones D.H., Read M.A., Saunders W., Colless M., Jarrett T., Parker Q.A., Fairall A.P., Mauch T., Sadler E.M., Watson F.G., Burton D., Campbell L.A., Cass P., Croom S.M., Dawe J., Fiegert K., Frankcombe L., Hartley M., Huchra J., James D., Kirby E., Lahav O., Lucey J., Mamon G.A., Moore L., Peterson B.A., Prior S., Proust D., Russell K., Safouris V., Wakamatsu K.-I., Westra E., Williams M. =2009MNRAS.399..683J ================================================================================ ADC_Keywords: Surveys; Galaxy catalogs; Redshifts; Galaxies, photometry Keywords: surveys - galaxies: distances and redshifts - cosmology: observations - large-scale structure of Universe Description: The final redshift release of the 6dF Galaxy Survey (6dFGS) is a combined redshift and peculiar velocity survey over the southern sky (|b|>10{deg}). Its 136304 spectra have yielded 110256 new extragalactic redshifts and a new catalogue of 125071 galaxies making near-complete samples with limits in (K, H, J, rF, bJ) (12.65, 12.95, 13.75, 15.60, 16.75). The median redshift of the survey is 0.053. The catalog includes basic data for the galaxies in the 6dFGS with redshifts, using the best 6dFGS redshifts (Q=3 or 4) plus available redshifts from SDSS, 2dFGRS and ZCAT (124647 entries in all). It supersedes the previous DR2 version (Cat. VII/249). The URL of the 6dFGS data base is: http://www-wfau.roe.ac.uk/6dFGS File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file 6dfgs.dat 178 124647 The 6dF Galaxy Survey Redshift Catalogue Data Release 3 (final release) spectra.dat 148 136304 Table of spectral observations -------------------------------------------------------------------------------- See also: http://www-wfau.roe.ac.uk/6dFGS : the 6dFGS home page VII/193 : The CfA Redshift Catalogue, Version June 1995 (Huchra+ 1995) VII/250 : The 2dF Galaxy Redshift Survey (2dFGRS) (2dFGRS Team, 1998-2003) II/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009) http://www.sdss.org : SDSS Home Page Byte-by-byte Description of file: 6dfgs.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 15 A15 --- 6dFGS Galaxy survey target ID (gHHMMSSs+DDMMSS) 18- 19 I2 h RAh Right ascension (J2000) 21- 22 I2 min RAm Right ascension (J2000) 24- 28 F5.2 s RAs [0,60] Right ascension (J2000) 31 A1 --- DE- Declination sign (J2000) 32- 33 I2 deg DEd Declination (J2000) 35- 36 I2 arcmin DEm Declination (J2000) 38- 41 F4.1 arcsec DEs [0,60] Declination (J2000) 44 I1 --- Nm Number of 6dFGS measurements (of any quality) 48 I1 --- Nz Number of measurements used in final cz (of quality 3 or 4 only) 50- 54 F5.2 mag bJmag Recalibrated b_J_ magnitude (BMAG) 56- 58 I3 --- PrID Programme ID number (PROGID in database) 60- 64 F5.2 mag rFmag Recalibrated r_F_ magnitude (RMAG) 67 I1 --- S/G [0/4] SuperCOSMOS star/galaxy classifier: 1=galaxy, 2=star, 3=unclassifiable, 4=noise 69- 70 I2 --- f_cz Comparison flags between z measurements (2) 72- 78 I7 km/s cz Best available combined recession velocity cz 80- 82 I3 km/s e_cz Combined uncertainty in cz (3) 84- 86 I3 --- r_cz Code identifying source of redshift (4) 89 I1 --- q_cz Best redshift quality value available (5) 92- 97 F6.2 deg GLON [0,360.0] Galactic longitude 99-104 F6.2 deg GLAT Galactic latitude 106-110 F5.2 mag AV Galactic extinction in V magnitudes (from Schlegel et al., 1998ApJ...500..525S) 112 I1 --- w Original weight source had for first round of fibre allocation 114-119 I6 --- Target [2/179260] TARGETID number in 6dFGS database 121-129 A9 --- Template Template code(s) (6) 131-148 A18 --- FileName Name of redshift field file containing the redshift (7) 150-178 A29 --- SpecID SPECID values of redshifts contributing to the final combined redshift -------------------------------------------------------------------------------- Note (2): The comparison threshold is 330km/s, and the flag is the sum of the following individual values: 0 = sole measurement or agreement within threshold 1 = >=1 6dFGS-6dFGS disagreement (median cz listed) 2 = >=1 6dFGS-ZCAT disagreement (6dFGS cz listed) 4 = >=1 6dFGS-2dFGRS disagreement (6dFGS cz listed) 8 = >=1 6dFGS-SDSS disagreement (6dFGS cz listed) 16 = >=1 6dFGS-ZCAT agreement (6dFGS cz listed) 32 = >=1 6dFGS-2dFGRS agreement (6dFGS cz listed) 64 = >=1 6dFGS-SDSS agreement (6dFGS cz listed) The 6dFGS cz values (Q=3,4) are listed in all cases in preference to the external value for redshift. ZCAT/2dFGRS/SDSS values are listed when no Q=3,4 6dFGS cz is available. Note that in the case of three or more 6dFGS measurements, just because one pair of 6dFGS measurements disagree, the redshift may in fact be secure through the remaining measurements. This can be checked against items Nmeas and Ncz. Note (3): Obtained by error-weighting individual redshifts, where Q=3 redshifts have uncertainty 55km/s and Q=4 have 45km/s. 6dFGS redshifts deemed unsuitable for extragalactic use (either because of measurement uncertainty or spectral classification) have had their uncertainties set to 0km/s. SDSS redshifts have an uncertainty of 30km/s (Abazajian et al., 2005AJ....129.1755A). 2dFGRS redshifts have uncertainties of 123km/s or 89km/s for redshift Q=3 or Q=4 respectively (Colless et al. 2001, Cat. ). and col. "q_cz" below). ZCAT redshifts carry the uncertainties from their original surveys and so vary. Note (4): Sources of redshift are: 0 = no (or unreliable 6dFGS) measure; 1..99 = ZCAT; 126 = 6dFGS; 250 = SDSS; 392 = 2dFGRS Note (5): Quality value as follows: 0 = no redshift quality value available 1 = 6dFGS or 2dFGRS, unusable measurement. 2 = 6dFGS or 2dFGRS, possible, but doubtful redshift estimate 3 = 6dFGS or 2dFGRS, 'probable' redshift (notionally 90% confidence) 4 = 6dFGS or 2dFGRS, reliable redshift (notionally 99% confidence) 6 = 6dFGS confirmed Galactic source 9 = SDSS and ZCAT sources (not a measure of quality) See Jones et al. (2004MNRAS.355..747J) or Colless et al. (2001, Cat. VII/250, 2001MNRAS.328.1039C) for details on the quality schemes used by 6dFGS and 2dFGRS respectively). Note (6): 6dFGS template if number, Z for ZCAT redshift, T for 2dFGRS, S for SDSS, or 0 if not available. 6dFGS template number (KBESTR) is 1 or 2 for early-type galaxy, 3, 4 or 5 for late-type galaxies. Note (7): Name of redshift field file if sourced from 6dFGS; or the words 2dFGRS, ZCAT, or SDSS if the redshift is from those surveys; otherwise "not_available" if the field information is not available, for whatever reason. -------------------------------------------------------------------------------- Byte-by-byte Description of file: spectra.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 6 I6 --- SpecID Unique ID number used for spectrum image 8- 13 I6 --- Target [1/500528] TARGETID number in 6dFGS database 15- 29 A15 --- 6dFGS Matching name in target table, used to name FITS files and generate thumbnail images 31- 32 I2 h RAh Observed right ascension (J2000) 33 A1 --- --- [:] 34- 35 I2 min RAm Observed right ascension (J2000) 36 A1 --- --- [:] 37- 41 F5.2 s RAs [0/60] Observed right ascension (J2000) 43 A1 --- DE- Observed Declination sign (J2000) 44- 45 I2 deg DEd Observed Declination (J2000) 46 A1 --- --- [:] 47- 48 I2 arcmin DEm Observed Declination (J2000) 49 A1 --- --- [:] 50- 53 F4.1 arcsec DEs [0/60] Observed Declination (J2000) 55- 60 F6.3 arcsec dr ?=-9.99 Position match error (arcsec) 63- 70 F8.5 --- zraw ?=-9.999 Raw measured redshift 72- 79 F8.5 --- z ?=-9.999 Heliocentric redshift 81 I1 --- q_z [0/6] Redshift measurement quality: 4=good to 1=bad (6=star) 83- 88 F6.2 --- Rcor ?=-9.99 Cross-correlation peak 91- 94 I4 s ExpV V reference frame exposure time seconds 96-103 F8.2 d MJD.V ?=0 MJD of observation in V band 106-109 I4 s ExpR R reference frame exposure time seconds 111-118 F8.2 d MJD.R ?=0 MJD of observation in R band 120-148 A29 --- Com Comments on redshift -------------------------------------------------------------------------------- History: Copied at http://www-wfau.roe.ac.uk/6dFGS/download.html ================================================================================ (End) Patricia Vannier [CDS] 23-Feb-2010