J/A+A/457/79   VIMOS VLT Deep Survey: faint type-1 AGN sample (Gavignaud+, 2006)
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The VIMOS VLT Deep Survey: the faint type-1 AGN sample.
    Gavignaud I., Bongiorno A., Paltani S., Mathez G., Zamorani G., Moller P.,
    Picat J.P., Le Brun V., Marano B., Le Fevre O., Bottini D., Garilli B.,
    Maccagni D., Scaramella R., Scodeggio M., Tresse L., Vettolani G.,
    Zanichelli A., Adami C., Arnaboldi M., Arnouts S., Bardelli S.,
    Bolzonella M., Cappi A., Charlot S., Ciliegi P., Contini T., Foucaud S.,
    Franzetti P., Guzzo L., Ilbert O., Iovino A., Mccracken H.J., Marinoni C.,
    Mazure A., Meneux B., Merighi R., Pello R., Pollo A., Pozzetti L.,
    Radovich M., Zucca E., Bondi M., Busarello G., Cucciati O., De La Torre S.,
    Gregorini L., Lamareille F., Mellier Y., Merluzzi P., Ripepi V., Rizzo D.,
    Vergani D.
   <Astron. Astrophys., 457, 79-90 (2006)>
   =2006A&A...457...79G
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ADC_Keywords: Surveys ; Active gal. nuclei ; Redshifts ; Photometry, UBVRI
Keywords: catalogs - surveys - galaxies: active - galaxies: Seyfert -
          quasars: general

Abstract:
    We present the type-1 active galactic nuclei (AGN) sample extracted
    from the VIMOS VLT Deep Survey's first observations of 21000 spectra
    in 1.75{deg}^2^. This sample, which is purely magnitude-limited and
    free of morphological or color-selection biases, contains 130
    broad-line AGN (BLAGN) spectra with redshift up to 5. Our data are
    divided into a wide (I_AB_<=22.5) and a deep (I_AB_<=24) subsample
    containing 56 and 74 objects, respectively. Because of its depth and
    selection criteria, this sample is uniquely suited for studying the
    population of faint type-1 AGN. Our measured surface density
    (~472+/-48 BLAGN per square degree with I_AB_<=24) is significantly
    higher than that of any other optically selected sample of BLAGN with
    spectroscopic confirmation. By applying a morphological and color
    analysis to our AGN sample, we find that (1) ~23% of the AGN brighter
    than I_AB_=22.5 are classified as extended, and this percentage
    increases to ~42 for those with z<1.6; (2) a non-negligible fraction
    of our BLAGN are lying close to the color-space area occupied by stars
    in the u*-g' versus g'-r' color-color diagram. This leads us to the
    conclusion that the classical optical-ultraviolet preselection
    technique, if employed at such deep magnitudes (I_AB_=22.5) in
    conjuction with a preselection of point-like sources, can miss up to
    ~35% of the AGN population. Finally, we present a composite spectrum
    of our sample of objects. While the continuum shape is very similar to
    that of the SDSS composite at short wavelengths, it is much redder
    than that of the SDSS composite at {lambda}>=3000{AA}. We interpret
    this as due to significant contamination from emission of the host
    galaxies, as expected from the faint absolute magnitudes sampled by
    our survey.

Description:
    The B, V, R, and I observations were performed from November 1999 to
    October 2000 at the 3.6m Canada-France-Hawaii Telescope, with the
    CFH12K wide-field mosaic camera.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
tablea1.dat    93      115   Broad-line AGN (BLAGN) with secure redshift
                              (flags 14 and 13)
tablea2.dat   119       15   BLAGN with a single emission line detected  and
                              more than one possible redshift (flag 19)
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See also:
          III/250 : The VIMOS VLT deep survey (VVDS-DEEP) (Le Fevre+ 2005)
   J/A+A/428/1043 : Redshifts from VIMOS VLT Deep Survey (Le Fevre+, 2004)

Byte-by-byte Description of file: tablea1.dat
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   Bytes Format Units   Label     Explanations
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   1-  7  A7    ---     Field     Field
       9  A1    ---     Sample    [dw] deep (d, I_AB_<=22.5) or
                                       wide (w, I_AB_<=24) sample
  11- 12  I2    ---     Nagn      Number of AGN in the field
  14- 22  I9    ---     VVDS      Object designation number
  24- 25  I2    h       RAh       Right ascension (J2000)
  27- 28  I2    min     RAm       Right ascension (J2000)
  30- 34  F5.2  s       RAs       Right ascension (J2000)
      36  A1    ---     DE-       Declination sign (J2000)
  37- 38  I2    deg     DEd       Declination (J2000)
  40- 41  I2    arcmin  DEm       Declination (J2000)
  43- 47  F5.2  arcsec  DEs       Declination (J2000)
  49- 54  F6.4  ---     z         Redshift
  56- 57  I2    ---     Flag      [13,14] BLAGN flag (1)
      58  A1    ---   n_Flag      [SF] Note on Flag (2)
  60- 64  F5.2  mag     Imag      I magnitude in AB system
  66- 70  F5.2  mag     Bmag      ?=- B magnitude in AB system
  72- 76  F5.2  mag     Vmag      ?=- V magnitude in AB system
  78- 82  F5.2  mag     Rmag      ?=- R magnitude in AB system
  84- 93  A10   ---     Morph     Morphological classification for objects
                                   with I_AB_<22.5 (G1)
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Note (1): Flags as follows:
     13 = BLAGN with only one line detection but with the redshift
          secured from other informations such as:
          - no other possible identification for the given wavelength range
          - an intervening absorption-line system is detected, which this
            leaves only one redshift solution for the BLAGN
          - strong iron features, so-called "bumps", are detected
          - a second line is marginally detected
     14 = BLAGN with secure redshift measurement (i.e.: two lines or more)

Note (2): Note on Flags as follows:
      F = AGN re-observed in the 3800-6500 range with FORS1 in our
          follow-up program.
      S = Redshift confirmed by matching the catalog from
          Szokoly et al. (2004, Cat. <J/ApJS/155/271>).
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Byte-by-byte Description of file: tablea2.dat
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   Bytes Format Units   Label     Explanations
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   1-  7  A7    ---     Field     Field
       9  A1    ---     Sample    [dw] deep (d, I_AB_<=22.5) or
                                       wide (w, I_AB_<=24) sample
  11- 12  I2    ---     Nagn      Number of AGN in the field
  14- 22  I9    ---     VVDS      Object designation number
  24- 25  I2    h       RAh       Right ascension (J2000)
  27- 28  I2    min     RAm       Right ascension (J2000)
  30- 34  F5.2  s       RAs       Right ascension (J2000)
      36  A1    ---     DE-       Declination sign (J2000)
  37- 38  I2    deg     DEd       Declination (J2000)
  40- 41  I2    arcmin  DEm       Declination (J2000)
  43- 47  F5.2  arcsec  DEs       Declination (J2000)
  49- 52  I4    0.1nm   lambda    Wavelength observed
  54- 59  F6.4  ---     z1        Redshift solution
      60  A1    ---   n_z1        [a-d] identification of the emission line (1)
  62- 67  F6.4  ---     z2        Redshift solution
      68  A1    ---   n_z2        [a-d] identification of the emission line (1)
  70- 75  F6.4  ---     z3        ? Redshift solution
      76  A1    ---   n_z3        [a-d] identification of the emission line (1)
  78- 83  F6.4  ---     z4        ? Redshift solution
      84  A1    ---   n_z4        [a-d] identification of the emission line (1)
  86- 90  F5.2  mag     Imag      I magnitude in AB system
  92- 96  F5.2  mag     Bmag      ?=- B magnitude in AB system
  98-102  F5.2  mag     Vmag      ?=- V magnitude in AB system
 104-108  F5.2  mag     Rmag      ?=- R magnitude in AB system
 110-119  A10   ---     Morph     Morphological classification for objects
                                   with I_AB_<22.5 (G1)
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Note (1): Note on redshift solution as follows:
      a = Emission line identified as H{alpha}
      b = Emission line identified as MgII
      c = Emission line identified as C III]
      d = Emission line identified as CIV
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Global notes:
Note (G1): Objects in the VVDS-CDFS field are not classified. See Sect. 7.1.
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History:
    From electronic version of the journal
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(End)                                      Patricia Vannier [CDS]    30-Apr-2007
