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J/ApJS/121/473      A diagnostic diagram for Seyfert 2 Galaxies (Bassani+, 1999)
A Three-dimensional Diagnostic Diagram for Seyfert 2 Galaxies:
Probing X-Ray Absorption and Compton Thickness
       Bassani L., Dadina M., Maiolino R., Salvati M., Risaliti G.,
       Della Ceca R., Matt G., Zamorani G.
      <Astrophys. J. Suppl. Ser. 121, 473 (1999)>
      =1999ApJS..121..473B      (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, Seyfert; X-ray sources

Keywords: galaxies: Seyfert - X-rays: galaxies


Abstract:
    We present and discuss a three-dimensional diagnostic diagram for
    Seyfert 2 galaxies obtained using X-ray and [O III] data on a large
    sample of objects (reported in the Appendix). The diagram shows the
    Kα iron line equivalent width as a function of both the column
    density derived from the photoelectric cutoff and the 2-10 keV flux
    normalized to the [O III] optical-line flux (the latter corrected for
    extinction and assumed to be a true indicator of the source intrinsic
    luminosity). We find that the hard X-ray properties of type 2 objects
    depend on a single parameter, the absorbing column density along the
    line of sight, in accordance with the unified model. The diagram can
    be used to identify Compton-thick sources and to isolate and study
    peculiar objects. From this analysis we have obtained a column density
    distribution of Seyfert 2 galaxies that is thought to be a good
    approximation of the real distribution. A large population of heavily
    absorbed objects is discovered, including many Compton-thick
    candidates. Our results indicate that the mean log NHcm-2 in type
    2 Seyfert galaxies is 23.5 and that as many as 23%-30% of sources
    have NH=>1024cm-2.

File Summary:

       FileName      Lrecl  Records   Explanations

ReadMe            80        .   This file
table1.dat       130       73   Catalog of Seyfert 2 Galaxies
table2.dat       131       73   Seyfert 2 spectral parameters
refs.dat         140       98   References for table1.dat and table2.dat


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

   Bytes Format Units        Label     Explanations

   1- 19  A19   ---          Name      Seyfert galaxy name
  21- 22  I2    h            RAh       Right Ascension (J2000)
  24- 25  I2    min          RAm       Right Ascension (J2000)
  27- 30  F4.1  s            RAs       Right Ascension (J2000)
      33  A1    ---          DE-       Sign of the Declination (J2000)
  34- 35  I2    deg          DEd       Declination (J2000)
  37- 38  I2    arcmin       DEm       Declination (J2000)
  40- 41  I2    arcsec       DEs       Declination (J2000)
  43- 50  F8.5  ---          z         Redshift
  52- 63  A12   ---          Class     Seyfert classification: S=Seyfert,
                                        L=Liner, SB=Starburst
  64- 70  A7    ---          r_z       Reference for z and Class in refs.dat
  72- 76  F5.2  10+20cm-2    ColD      Galactic H I column density
      82  A1    ---          l_Rat     Limit on Rat
  83- 87  F5.2  ---          Rat       ? Ratio of Hα to H[beta
  90- 99  A10   ---          r_ColD    References for ColD and Rat in refs.dat
     101  A1    ---          l_OIII    Limit on OIII
 102-107  F6.3  10-11mW/m2   OIII      ? Corrected [O III] flux
 109-113  F5.3  10-11mW/m2   e_OIII    ? uncertainty on the [O III] flux
     118  A1    ---          n_OIII    Remark on OIII (1)
 121-130  A10   ---          r_OIII    References for OIII in refs.dat

Note (1): For this object, the only [O III] measurement available was taken
    with an aperture smaller than 100 pc as projected on the source, and
    therefore these data are likely to miss a significant fraction of the
    [O III] flux


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

   Bytes Format Units        Label     Explanations

   1- 19  A19   ---          Name      Seyfert Galaxy name
      21  A1    ---          n_Name    [ehg] Name flag (1)
  24- 28  F5.2  ---          Gamma     The photon index
  30- 34  F5.2  ---          E_Gamma   ? upper limit on Gamma
  36- 40  F5.2  ---          e_Gamma   ? lower limit on Gamma
      42  A1    ---          n_Gamma   [fj] note on Gamma: f = Fixed photon
                                        index, j = Parameter is pegged at
                                        the higher limit
      45  A1    ---          l_ColD    Lower limit on ColD
  46- 52  F7.1  10+20cm-2    ColD      Hydrogen column density
      55  A1    ---          n_ColD    Flag indicating ColD and p_ColD is a
                                        range
  58- 64  F7.1  10+20cm-2    E_ColD    ? Upper limit on ColD
  67- 74  F8.1  10+20cm-2    e_ColD    ? Lower limit on ColD
      76  A1    ---          f_ColD    [d] Indicates parameter is pegged at
                                        lower limit
      78  A1    ---          l_EW      Lower limit on EW
  79- 83  I5    eV           EW        ? Iron Kα line equivalent width
  85- 90  I6    eV           E_EW      ? Upper limit on EW
  93- 98  I6    eV           e_EW      ? Lower limit on EW
     100  A1    ---          n_EW      Flag indicating line in EW is at 6.7 KeV
 103-108  F6.4  10-11mW/m2   Fxo       Observed flux between 2-10 KeV
 112-118  F7.4  10-11mW/m2   Fxc       Absorption corrected flux between
                                        2-10 KeV
     120  A1    ---          n_Fxc     Flag indicating Fxc is the lower value
 124-127  F4.2  10-11mW/m2   E_Fxc     ? Upper absorption corrected flux
                                        between 2-10 KeV
 130-131  I2    ---          r_Name    References in refs.dat

Note (1):
    e = Compton-thick source with NH=>1025cm-2
    g = Compton-thick source with NH=>1024cm-2
    h = X-ray emission possibly dominated by a cooling flow around
        F09104+4109 (Fabian & Crawford, 1995MNRAS..274L..63F) and by
        intracluster emission in Cygnus A (Ueno+, 1994ApJ..431L..1U)


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

   Bytes Format Units   Label     Explanations

   1-  2  I2    ---     Seq       Sequence number from table1.dat
   5- 23  A19   ---     Bibcode   Reference code sequence
  26-140  A115  ---     Com       Comments on references


History:
    From ApJ electronic edition
(End)                            Greg Schwarz (AAS)                  01-Feb-2000