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J/AJ/128/1002      SDSS candidate type II quasars. II          (Zakamska+, 2004)
Candidate type II quasars from the Sloan Digital Sky Survey.
II. From radio to x-rays.
    Zakamska N.L., Strauss M.A., Heckman T.M., Ivezic Z., Krolik J.H.
   <Astron. J., 128, 1002-1016 (2004)>
   =2004AJ....128.1002Z
ADC_Keywords: Active gal. nuclei ; QSOs ; Galaxies, IR ; Galaxies, radio ;
              X-ray sources ; Redshifts
Keywords: galaxies: active - infrared: galaxies - quasars: general - surveys -
          X-rays: galaxies

Abstract:
    Type II quasars are luminous active galactic nuclei (AGNs) whose
    central engines and broad-line regions are obscured by intervening
    material; such objects only recently have been discovered in
    appreciable numbers. We study the multiwavelength properties of 291
    type II AGN candidates (0.3<z<0.8) selected on the basis of their
    optical emission-line properties from the spectroscopic database of
    the Sloan Digital Sky Survey (Cat. J/AJ/126/2579). This sample
    includes about 150 objects luminous enough to be classified as type II
    quasars. We matched the sample to the FIRST (20cm, Cat.VIII/71),
    IRAS (12-100µm, Cat. II/125), 2MASS (JHKs, Cat. II/246), and
    RASS (0.1-2.4keV, Cat. IX/29) surveys. Roughly 10% of optically
    selected type II AGN candidates are radio-loud, comparable to the AGN
    population as a whole. About 40 objects are detected by IRAS at 60
    and/or 100µm, and the inferred mid/far-IR luminosities lie in the
    range L=1045-3x1046ergs/s. Average IR-to-[OIII]λ5007 ratios
    of objects in our sample are consistent with those of other AGNs.
    Objects from our sample are 10 times less likely to have soft X-ray
    counterparts in RASS than type I AGNs with the same redshifts and
    [OIII]λ5007 luminosities. The few type II AGN candidates from
    our sample that are detected by RASS have harder X-ray spectra than
    those of type I AGNs. The multiwavelength properties of the type II
    AGN candidates from our sample are consistent with their
    interpretation as powerful obscured AGNs.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat        63      143   FIRST Matches of Type II AGNs
table2.dat        69        5   Radio Matches of Type II AGNs Not Covered by FIRST
table3.dat        64       74   IRAS Counterparts of Type II AGNs
table4.dat        72        6   RASS Counterparts of Type II AGNs


See also:
  J/AJ/126/2125 : SDSS candidate type II quasars (Zakamska+, 2003)
  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)
  VIII/71       : The FIRST Survey Catalog, Version 03Apr11 (Becker+ 2003)
  II/125        : IRAS catalogue of Point Sources, Version 2.0 (IPAC 1986)
  II/246        : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
  IX/10         : ROSAT All-Sky Bright Source Catalogue (1RXS)
  IX/29         : ROSAT All-Sky Survey Faint Source Catalog (Voges+ 2000)


Byte-by-byte Description of file: table1.dat

   Bytes Format Units   Label     Explanations

   1-  4  A4    ---     ---       [SDSS]
   6- 24  A19   ---     SDSS      SDSS Name, based on J2000.0 position (G1)
  26- 30  F5.3  ---     z         Redshift
  32- 36  F5.2 [solLum] logLum    Log of [OIII]λ(5007) luminosity in
                                   solar units
  38- 43  F6.1  mJy     F20cmc    FIRST (20cm) core flux (1.5GHz)
  45- 50  F6.1  mJy     F20cmt    20cm total flux
  52- 55  F4.1  ---     Sp+Index  ? Spectral index
      57  I1    ---     Morph     [1/2] Morphology code (1)
  59- 62  A4    ---     Ref       References (2)

Note (1): The morphology code is defined as follows:
    1 = Unresolved by FIRST (Cat. VIII/71) and NVSS (Cat. VIII/65);
    2 = Resolved by FIRST (Cat. VIII/71) or NVSS (Cat. VIII/65).
Note (2): References:
    1 = Condon et al. 1998, Cat. VIII/65 (NVSS)--if this reference is listed
         it means that the total flux was taken from the NVSS;
    2 = Gregory et al. 1996, Cat. VIII/40 (GB6);
    3 = Rengelink et al. 1997, Cat. J/A+AS/124/259 (WENSS);
    4 = Other (NED).


Byte-by-byte Description of file: table2.dat

   Bytes Format Units   Label     Explanations

   1-  4  A4    ---     ---       [SDSS]
   6- 24  A19   ---     SDSS      SDSS Name, based on J2000.0 position (G1)
  27- 31  F5.3  ---     z         Redshift
  34- 37  F4.2 [solLum] logLum    Log of [OIII]λ(5007) luminosity in
                                  solar units
  40- 42  F3.1  arcmin  Offset    Offset between the optical and radio position
  45- 49  F5.1  mJy     F1.4GHz   Flux density at 1.4GHz
  51- 54  F4.1  ---     Sp+Index  ? Spectral Index
      57  I1    ---     Morph     [1/2] Morphology code (1)
  60- 69  A10   ---     Ref       References (2)

Note (1): The morphology code is based on the NVSS (Cat. VIII/65)
      images and defined as follows:
    1 = a point source;
    2 = an extended source.
Note (2): References:
    1 = Condon et al. 1998, Cat. VIII/65;
    2 = Gregory et al. 1996, Cat. VIII/40;
    3 = Rengelink et al. 1997, Cat. J/A+AS/124/259;
    4 = other (NED).


Byte-by-byte Description of file: table3.dat

   Bytes Format Units    Label    Explanations

   1-  4  A4    ---      ---      [SDSS]
   6- 24  A19   ---      SDSS     SDSS Name, based on J2000.0 position (G1)
  26- 30  F5.3  ---      z        Redshift
  32- 36  F5.2  [solLum] logLum   Log of [OIII]λ(5007) luminosity in
                                   solar units
  38- 40  I3    mJy      F60um    ? Flux at 60 microns
  42- 43  I2    mJy      e_F60um  ? Nominal error in F60um
  45- 48  F4.2  ---      c60um    ? Confidence level of the 60 micron detection
  50- 53  I4    mJy      F100um   ? Flux at 100 microns
  55- 57  I3    mJy     e_F100um  ? Nominal error in F100um
  59- 62  F4.2  ---      c100um   ? Confidence level of the 100 micron detection


Byte-by-byte Description of file: table4.dat

   Bytes Format Units   Label     Explanations

   1-  4  A4    ---     ---       [SDSS]
   6- 24  A19   ---     SDSS      SDSS Name, based on J2000.0 position (G1)
  27- 31  F5.3  ---     z         Redshift
  34- 37  F4.2 [solLum] logLum    Log of [OIII]λ(5007) luminosity in
                                   solar units
  40- 43  F4.2  arcmin  Offset    Offset between the SDSS and the RASS positions
  46- 50  F5.3  ct/s    CR        Count rate
  53- 55  F3.1  ---     HR1       Hardness ratio 1 (1)
  58- 60  F3.1  ---     HR2       Hardness ratio 2 (1)
  63- 67  F5.2  [10-7W] logLX     log(LX) in units of erg/s
  70- 72  A3    ---     Com       [yes no] Radio-loud ?

Note (1): Hardness ratios HR1 and HR2 are defined in Voges et al.
    (1999, Cat. IX/10A). From the source counts in the band A and the
    band B HR1 is given by: HR1=(B-A)/(B+A). HR2 is determined from the
    source counts in the bands C and D by: HR2=(D-C)/(D+C). Since
    background subtraction is involved, the source counts in some bands
    may be negative. Both values can vary between -1 and 1.


Global Notes:

Note (G1): J2000.0 coordinates are given as hhmmss.ss+ddmmss.s.



History:
    From electronic version of the journal

References:
  Zakamska et al., Paper I  2003AJ....126.2125Z, Cat. J/AJ/126/2125
(End)                   Greg Schwarz [AAS], Marianne Brouty [CDS]    07-Mar-2005