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J/ApJ/462/614       A deep multicolor survey. II. (Hall+ 1996)
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A deep multicolor survey. II. Initial spectroscopy and comparison
with expected quasar number counts.
    Hall P.B., Osmer P.S., Green R.F., Porter A.C., Warren S.J.
   <Astrophys. J. 462, 614 (1996)>
   =1996ApJ...462..614H (SIMBAD/NED BibCode)
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ADC_Keywords: QSOs ; Galaxies, photometry ; Surveys
Keywords: catalogs - galaxies: photometry - quasars: general - surveys

Description:
    We have used the Kitt Peak National Observatory 4m Mayall telescope to
    image 0.83 square degrees of sky in six fields at high galactic
    latitude in six filters spanning 3000-10000A to magnitude limits
    ranging from 22.1 to 23.8. As a first use of this database, we have
    conducted a multicolor survey for quasars. We discuss various methods
    of selecting outliers in different color-color diagrams and multicolor
    space that have been used to identify quasars at all redshifts from
    their colors alone. We discuss the initial results of our program of
    spectroscopic identification which has so far resulted in the
    identification of over 40 faint quasars, including one a z>4, a
    similar number of compact narrow emission-line galaxies, and a number
    of unusual and potentially interesting stars. We use these
    spectroscopic results, along with extensive simulations of quasar
    spectra, to study the efficiency of our candidate selection
    procedures. Finally, we compare the number counts of our quasars
    and quasar candidates to the expected numbers based on previous
    studies of the quasar luminosity function. The agreement of our
    observations with these expectations is good in most cases. However,
    we do estimate that our survey contains more quasars with B<21 and
    z<2.3 than expected from the results published by Koo & Kron in
    (1988ApJ...325...92K) and more z>3 quasars than expected from the
    results published by Warren, Hewett & Osmer in (1994ApJ...421..412W),
    both at the 3 {sigma} level. Additional spectroscopic observations
    will be required to confirm or refute these excesses.

File Summary:
--------------------------------------------------------------------------------
  FileName Lrecl Records  Explanations
--------------------------------------------------------------------------------
ReadMe        80       .  This file
table1.dat    71      46  Quasars: identification
table1.tex    86      64  LaTeX version of table1
table2.dat    72      39  Compact narrow emission-line galaxies: identifications
table2.tex    87      58  LaTex Version of table2
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See also:
    J/ApJS/104/185 : A deep multicolor survey. I. (Hall+ 1996)
    J/AJ/114/2269  : A deep multicolor survey. III (Kennefick+ 1997)
    J/ApJS/119/189 : A deep multicolor Survey. IV. (Osmer+ 1998)

Byte-by-byte Description of file: table1.dat table2.dat
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   Bytes Format Units   Label     Explanations
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   1-  2  I2    ---     No        Sequential number
   4- 17  A14   ---     Name      DMS or N designation (1)
  19- 20  I2    h       RAh       Right ascension (1950.0)
  22- 23  I2    min     RAm       Right ascension (1950.0)
  25- 29  F5.2  s       RAs       Right ascension (1950.0)
      31  A1    ---     DE-       Declination sign
  32- 33  I2    deg     DEd       Declination (1950.0)
  35- 36  I2    arcmin  DEm       Declination (1950.0)
  38- 42  F5.2  arcsec  DEs       Declination (1950.0)
  44- 47  F4.1  mag     Bmag      B magnitude
  49- 53  F5.3  ---     z         ? Redshift
      54  A1    ---   u_z         [?] Uncertainty flag on z
  56- 72  A17   ---     Notes     Notes
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Note (1): DMS followed by the epoch 1950.0 position in table1.dat,
          N followed by the epoch 1950.0 position in table2.dat
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Acknowledgements: Pat Hall <pathall@as.arizona.edu>
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(End)                                         Patricia Bauer  [CDS]  03-Oct-1996