ACDS V10.0 - Detailed Description of VII/241

ACDS V10.0 - Sun Jan 19 06:27:57 CET 2025

| # Detailed Description of VII/241 : The 2dF QSO Redshift Survey (Croom+ 2004) |

Note : this is the description file of the original catalog. This HTML page corresponds well to the original description, but some minor changes in the format may have been introduced in the FITS output files in order to allow for arithmetic operations on quantities such as coordinates and times. h:m:s and d:m:s units are normally converted into degrees, and YYYY-MM-DD into julian days.
Similarly, some slight changes may have been introduced in the units; the value given in the HTML files supersedes the value indicated in the ReadMe file for this catalogue.

    VII/241             The 2dF QSO Redshift Survey                (Croom+ 2004)
    ================================================================================
    The 2dF QSO Redshift Survey (2QZ)
         Croom S.M., Smith R.J., Boyle B.J., Shanks T., Miller L., Outram P.J.,
         Loaring N.S.
        <Mon. Not. R. Astron. Soc. 349, 1397 (2004)>
        =2004MNRAS.349.1397C
    ================================================================================
    ADC_Keywords: Active gal. nuclei; QSOs; Redshifts; Spectroscopy;
                  Stars, white dwarf; Stars, normal; Galaxies, spectra
    Keywords: catalogues - surveys - white dwarfs - galaxies: active -
              quasars: general - galaxies: Seyfert

    Abstract:
        The final catalogue of the 2dF QSO Redshift Survey (2QZ) is based on
        Anglo-Australian Telescope 2dF spectroscopic observations of 44576
        colour-selected (ubJr) objects with 18.25<bJ< 20.85 selected from
        automated plate measurement scans of UK Schmidt Telescope (UKST)
        photographic plates. The 2QZ comprises 23338 quasi-stellar objects
        (QSOs), 12292 galactic stars (including 2071 white dwarfs) and 4558
        compact narrow emission-line galaxies. We obtained a reliable
        spectroscopic identification for 86 per cent of objects observed with
        2dF. We also report on the 6dF QSO Redshift Survey (6QZ), based on
        UKST 6dF observations of 1564 brighter (16<bJ<18.25) sources selected
        from the same photographic input catalogue. In total, we identified
        322 QSOs spectroscopically in the 6QZ. The completed 2QZ is, by more
        than a factor of 50, the largest homogeneous QSO catalogue ever
        constructed at these faint limits (bJ<20.85) and high QSO surface
        densities (35 QSOs/deg2). As such, it represents an important
        resource in the study of the Universe at moderate-to-high redshifts.

    Description:
        Spectroscopic observations of the input catalogue were made with the
        2dF instrument at the Anglo-Australian Telescope (AAT; the 2QZ sample)
        and the 6dF instrument at the UKST (the 6QZ sample). 2dF spectroscopic
        observations began in January 1997 and were completed in April 2002.

        Six-degree Field observations were performed over the period 2001
        March-2002 September.

    File Summary:

           FileName      Lrecl  Records   Explanations

    ×                   80        .   This file
    × ReadMe            80        .   This file
    × 2qz.dat          354    49425   2QZ catalogue: includes North and South galactic
                                 poles, and 6QZ with another 1657 lines.
    × ngp_rep.dat      145      926   Additional spectra when more than 2 spectra (NGP)
    × sgp_rep.dat      145     1047   Additional spectra when more than 2 spectra (SGP)
    × 6qz_rep.dat      145       87   Additional spectra when more than 2 spectra (6QZ)

    See also:
        http://www.2dfquasar.org/ : the 2QZ Home Page
        II/268 : 2QZ Photometric Catalog (Croom et al., 2005)
        VII/235 : Quasars and Active Galactic Nuclei (11th Ed.) (Veron+, 2003)

    Byte-by-byte Description of file:  2qz.dat

       Bytes Format Units    Label    Explanations

       1- 16  A16   ---      2QZ      Name of the source in 2QZ (JHHMMSS.S+DDMMSS)
      18- 19  I2    h        RAh      Right ascension (J2000)
      21- 22  I2    min      RAm      Right ascension (J2000)
      24- 28  F5.2  s        RAs      Right ascension (J2000)
          30  A1    ---      DE-      Declination sign (J2000)
      31- 32  I2    deg      DEd      Declination (J2000)
      34- 35  I2    arcmin   DEm      Declination (J2000)
      37- 40  F4.1  arcsec   DEs      Declination (J2000)
      42- 46  I5    ---      intNo    Internal catalog object number
      48- 57  A10   ---      intName  Internal name of the object
      59- 83  A25   ---      Sector   Name of the sector this object inhabits
      85- 86  I2    h        RA1950h  Right Ascension B1950 (hours)
      88- 89  I2    min      RA1950m  Right Ascension B1950 (minutes)
      91- 95  F5.2  s        RA1950s  Right Ascension B1950 (seconds)
          97  A1    ---      DE1950-  Declination B1950 (sign)
      98- 99  I2    deg      DE1950d  Declination B1950 (degrees)
     101-102  I2    arcmin   DE1950m  Declination B1950 (minutes)
     104-107  F4.1  arcsec   DE1950s  Declination B1950 (seconds)
     109-111  I3    ---      Field    UKST Survey field number
     113-121  F9.2  pix      Xpos     APM scan X position (1pix=8um)
     123-131  F9.2  pix      Ypos     APM scan Y position (1pix=8um)
     133-143  F11.8 rad      RArad    Right ascension B1950 (radians)
     145-155  F11.8 rad      DErad    Declination B1950 (radians)
     160-165  F6.3  mag      bJmag    bJ magnitude
     170-175  F6.3  mag      u-bJ     u-bJ colour index
     179-185  F7.3  mag      bJ-r     bJ-r colour index (G1)
         189  I1    ---      Nsp      Number of observations (1)
     191-196  F6.4  ---      z1       Redshift from first spectrum
     198-199  I2    ---      q_z1     Quality flag for first spectrum (G3)
     201-209  A9    ---      ID1      Identification for first spectrum (G4)
     212-219  I8  "YYYYMMDD" Date1    ? Date of observation for first spectrum
     221-224  I4    ---      Field1   field and spectrograph for first spectrum (G2)
     226-228  I3    ---      Fiber1   2dF fiber number
     231-236  F6.2  ---      S/N1     Signal-to-noise ratio for first spectrum (G5)
     238-243  F6.4  ---      z2       ?=0 Redshift from second spectrum
     245-246  I2    ---      q_z2     Quality flag for second spectrum (G3)
     248-256  A9    ---      ID2      Identification for second spectrum  (G4)
     259-266  I8  "YYYYMMDD" Date2    ? Date of observation for second spectrum
     268-271  I4    ---      Field2   field and spectrograph for 2nd spectrum (G2)
     273-275  I3    ---      Fiber2   2dF fiber number
     278-283  F6.2  ---      S/N2     Signal-to-noise ratio for second spectrum (G5)
     285-289  F5.3  ---      zprev    ?=0 Redshift if previously known (2)
     291-294  I4    mJy      F21cm    ?=0 Flux at 1.4GHz from NVSS (3)
     295-296  A2    ---      ---      [.0]
     298-304  F7.4 10-16W/m2 FX       ?=0 Flux at 0.1-2.4keV from RASS (4)
     306-312  F7.5  mag      E(B-V)   Reddening E(B-V) from Schegel et al.,
                                      1998ApJ...500..525S
     314-333  A20   ---      Com1     Specific Comment on observation 1
     335-354  A20   ---      Com2     Specific Comment on observation 2

    Note (1): The number of independent spectra taken.
         The highest quality spectrum is always spectrum 1.
         When there are more than 2 spectra, details of the additional
         spectral are given in the files ngp_rep.dat, sgp_rep.dat and
         6qz_rep.dat (North and South galactic poles, and 6QZ, respectively)
    Note (2): The previously known redshift is taken from the
         "Quasars and Active Galactic Nuclei (9th Ed.)", Veron-Cetty M.P.,
         Veron P., 2000, ESO Scientific Report 19, Cat. VII/215
    Note (3): 1.4GHz radio flux is taken from the NRAO VLA Sky Survey (NVSS),
         Condon et al., 1998AJ....115.1693C, Cat. VIII/65
    Note (4): The X-ray flux is taken from the ROSAT All Sky Survey,
        Voges et al., 1999A&A...349..389V, Cat. IX/10; Voges et al.,
        2000IAUC.7432R...1V. Counts/s in the 0.1 to 2.4keV band were converted
        to flux in 10-13erg/s/cm2 (or equivalently 10-13mW/m2) assuming
        a photon index of -2 giving a conversion factor of 5.6x10-12.

    Byte-by-byte Description of file:  ngp_rep.dat  sgp_rep.dat  6qz_rep.dat

       Bytes Format Units   Label     Explanations

       1- 16  A16   ---     2QZ       Name of the source in 2QZ (JHHMMSS.S+DDMMSS)
      18- 19  I2    h       RAh       Right ascension (J2000)
      21- 22  I2    min     RAm       Right ascension (J2000)
      24- 28  F5.2  s       RAs       Right ascension (J2000)
          30  A1    ---     DE-       Declination sign
      31- 32  I2    deg     DEd       Declination (J2000)
      34- 35  I2    arcmin  DEm       Declination (J2000)
      37- 40  F4.1  arcsec  DEs       Declination (J2000)
      42- 51  A10   ---     intName   Internal name of the object
      53- 58  F6.3  mag     bJmag     bJ magnitude
      61- 66  F6.3  mag     u-bJ      u-bJ colour index
      68- 74  F7.3  mag     bJ-r      bJ-r colour index (G1)
      76- 81  F6.4  ---     z         Redshift from first spectrum
      83- 84  I2    ---     q_z       Quality flag for first spectrum (G3)
      86- 94  A9    ---     ID        Identification for first spectrum (G4)
      97-104  I8 "YYYYMMDD" Date      ? Date of observation for first spectrum
     106-109  I4    ---     Field     field and spectrograph for first spectrum (G2)
     111-113  I3    ---     Fiber     2dF fiber number
     115-120  F6.2  ---     S/N1      Signal-to-noise ratio for first spectrum (G5)
         121  A1    ---     ---       [0]
         124  I1    ---     No        [3,6] Observation number
     126-145  A20   ---     Com       Comment on observation

    Gloval Notes:

    Note (G1): In the case of an object having only an upper limit in the
        r-band, the bJ-r colour is defined as (bJ-rlim)-10. All r-band
        detections have bJ-r>-1.5 while this definition gives all upper
        limits bJ-r<-9.8.
    Note (G2): The number is defined as
         2dF field number x10 + 2dF spectrograph number
         e.g. field number 218 and spectrograph 2 gives 2182.
         (the spectrograph number is 1 or 2)
    Note (G3): Both redshift and identification are given separate quality
        flags (1 = high-quality, 2 = low-quality, 3 = unclassifiable).
        The quality number is set as
            identification quality x 10 + redshift quality
    Note (G4): The spectra are classified in six main categories:
          QSO = for a spectrum with broad emission lines
         NELG = (narrow-emission line galaxy) for a spectrum with narrow
                emission lines
          gal = a galaxy spectrum with no emission lines
         star = a Galactic star spectrum
         cont = a high signal-to-noise (S/N>10) spectrum with no identifiable
                emission of absorption features
           ?? = an unclassifiable spectrum

        Sub-classes are contained within parentheses after the main classifications:
           DA = a DA white dwarf
           DB = a DB white dwarf
           DO = a DO white dwarf
           DZ = a DZ white dwarf
           CV = a star with strong hydrogen Balmer emission lines
          DAM = a DA white dwarf - M-dwarf binary
          DBM = a DB white dwarf - M-dwarf binary
          BAL = a broad absorption line QSO

         For example QSO(BAL), star(DA), star(CV). If the identification
         has a class 2 quality then there is a ? appended to the end of
         the identification.
    Note (G5): Signal-to-noise calculated in a 400-490nm band

    History:
        From the 2QZ site at http://www.2dfquasar.org/
    ================================================================================
    (End)                                   Francois Ochsenbein [CDS]    01-Jun-2006