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J/ApJ/413/453  On the redshift-apparent size diagram of double (NILSSON 1993)
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On the redshift-apparent size diagram of double radio sources
    Nilsson K., Valtonen M.J., Kotilainen J., Jaakkola T.
    <Astrophys. J. 413, 453 (1993)>
    =1993ApJ...413..453N
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ADC_Keywords: Radio sources; Redshifts
Keywords: cosmology: observations - quasars: general -
          radio continuum: galaxies

Abstract:
   We review the data on the angular sizes of double radio sources. There is a
   positive correlation between the true radio source size and radio power 
   among low-luminosity radio galaxies. This may be partly explained through 
   sample selection effects. There is a negative correlation between radio 
   size and power among high luminosity radio galaxies and all quasars. It 
   follows the constant total energy envelope closely. There is no significant
   difference between the radio sizes of radio galaxies and quasars of the 
   same luminosity. However, it is possible that real differences in the radio
   sizes of the two populations are hidden by selection effects in our sample.
   The angular size-redshift diagram shows a deficiency of large radio sources
   at high redshifts which is fully explained by the above-mentioned negative 
   correlation without need for cosmic evolution of radio source size. However,
   the possibility of some cosmic evolution is not totally ruled out by the 
   data. 

File Summary:
--------------------------------------------------------------------------------
 FileName    Lrecl    Records    Explanations
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ReadMe          80          .    This file
refs.dat       170        201    References
reftab1.dat     42        163    References to table1
table1.dat      97        540    Double radio source data
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Byte-by-byte Description of file: table1.dat
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   Bytes Format  Units   Label    Explanations
--------------------------------------------------------------------------------
   1-  9  A9     ---     IAU      IAU name
  12- 20  A9     ---     Name     Other name
  24- 28  F5.3   ---     z        Spectroscopically measured redshift
  32- 37  F6.1   arcsec  LAS      Largest angular size
  40- 45  F6.1   kpc     size     True linear size
  53- 56  F4.1  [10-7W]  logL     Radio luminosity in the frequency interval
                                   10 MHz-10 GHz (erg/s)
  63- 67  F5.2   ---     alpha    Spectral index at the high-frequency end
                                   of the spectral range
      72  A1     ---     Id       [GQ] Type of the central object:
                                                                  G: galaxy
                                                                  Q: quasar
  80- 97  A18    ---     ref      References (in file reftab1)
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Byte-by-byte Description of file: reftab1.dat
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   Bytes Format  Units   Label    Explanations
--------------------------------------------------------------------------------
   1-  3  I3     ---     ref      Reference number
  12- 61  A50    ---     Names    Authors' names
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Courtesy: Kari Nilsson <kani@sirius.astro.utu.fi>
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(End)                                       Patricia Bauer   [CDS]   07-Jul-1994