J/AJ/126/2125       SDSS candidate type II quasars           (Zakamska+, 2003)
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Candidate type II quasars from the Sloan Digital Sky Survey.
I. Selection and optical properties of a sample at 0.3<z<0.83.
    Zakamska N.L., Strauss M.A., Krolik J.H., Collinge M.J., Hall P.B., Hao L.,
    Heckman T.M., Ivezic Z., Richards G.T., Schlegel D.J., Schneider D.P.,
    Strateva I., Vanden Berk D.E., Anderson S.F., Brinkmann J.
   <Astron. J., 126, 2125-2144 (2003)>
   =2003AJ....126.2125Z
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ADC_Keywords: QSOs ; Photometry, SDSS ; Spectroscopy
Keywords: galaxies: active - quasars: emission lines - quasars: general -
          surveys

Abstract:
    Type II quasars are the long-sought luminous analogs of type 2 (narrow
    emission line) Seyfert galaxies, suggested by unification models of
    active galactic nuclei (AGNs) and postulated to account for an
    appreciable fraction of the cosmic hard X-ray background. We present a
    sample of 291 type II AGNs at redshifts 0.3<z<0.83 from the
    spectroscopic data of the Sloan Digital Sky Survey. These objects have
    narrow (FWHM<2000km/s), high equivalent width emission lines with
    high-ionization line ratios. We describe the selection procedure and
    discuss the optical properties of the sample. About 50% of the objects
    have [O III] {lambda}5008 line luminosities in the range
    3x10^8^-10^10^L_{sun}_, comparable to those of luminous (-27<M_B_<-23)
    quasars; this, along with other evidence, suggests that the objects in
    the luminous subsample are type II quasars.

File Summary:
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 FileName   Lrecl  Records   Explanations
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ReadMe         80        .   This file
table1.dat    125      291   SDSS Type II AGNs at Redshifts 0.3<z<0.83
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See also:
  J/AJ/123/567  : SDSS quasar catalog, I: Early Data Release (Schneider+, 2002)
  J/AJ/126/2579 : SDSS quasar catalog. II. First data release (Schneider+, 2003)
  J/AJ/128/1002 : SDSS candidate type II quasars. II (Zakamska+, 2004)

Byte-by-byte Description of file: table1.dat
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   Bytes Format Units   Label    Explanations
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   1-  4  A4    ---     ---      [SDSS]
   6- 24  A19   ---     SDSS     The SDSS name (1)
      26  I1    ---     DR1      [0/1] Availability in Data Release 1
                                        (1 = Yes, 0 = No)
  28- 32  F5.3  ---     z        Redshift based on [O II] (3728) emission line
  34- 40  A7    ---     TCode    The seven-digit target code (2)
  42- 46  F5.2  mag     u*mag    SDSS u*-band PSF magnitude
  48- 51  F4.2  mag   e_u*mag    Error in u*mag
  53- 57  F5.2  mag     g*mag    SDSS g*-band PSF magnitude
  59- 62  F4.2  mag   e_g*mag    Error in g*mag
  64- 68  F5.2  mag     r*mag    SDSS r*-band PSF magnitude
  70- 73  F4.2  mag   e_r*mag    Error in r*mag
  75- 79  F5.2  mag     i*mag    SDSS i*-band PSF magnitude
  81- 84  F4.2  mag   e_i*mag    Error in i*mag
  86- 90  F5.2  mag     z*mag    SDSS z*-band PSF magnitude
  92- 95  F4.2  mag   e_z*mag    Error in z*mag
  97- 99  I3    0.1nm   EW[OII]  Equivalent width of [O II] (3728)
 101-104  I4    0.1nm   EW[OIII] Equivalent width of [O III] (5008)
 106-109  F4.2 [solLum] L[OII]   Log of [O II] (3728) luminosity
 111-115  F5.2 [solLum] L[OIII]  Log of [O III] (5008) luminosity
 117-123  F7.2  mJy     Flux     The FIRST 20cm flux (3)
     125  I1    ---     Com      [0/1] Asymmetric lines (1 = Yes, 0 = No)
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Note (1): Coordinates are given in the Name as hhmmss.ss+ddmmss.s (J2000).
Note (2): The targeting information is in the 5+2 digit target code 
    that shows how the object was targeted for spectroscopy. The first
    five digits indicate whether the object was targeted on one of the
    main spectroscopic plates by the Galaxy, LRG, Quasar, High-redshift
    quasar or Serendipity algorithms, in that order. A digit of 0 means
    the object was not targeted by this method, while 1 means targeted.
    The algorithms have different selection criteria and limiting
    magnitudes, as described in section 2. The last two digits show
    whether the object was targeted on one of the DSES or one of the
    Special plates.
Note (3): Note on Flux:
      0 = Not detected;
     -1 = The field was not observed by FIRST.
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History:
    From electronic version of the journal

References:
  Zakamska et al., Paper II  2004AJ....128.1002Z, Cat. <J/AJ/128/1002>

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(End)                    Greg Schwarz [AAS], Patricia Bauer [CDS]    19-Dec-2003