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1995AJ....110..880Johnston+

J/AJ/110/880                           Radio reference frame (Johnston+ 1995)
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A radio reference frame
     Johnston K.J., Fey A.L., Zacharias N., Russell J.L., Ma C., de  Vegt C.,
     Reynolds J.E., Jauncey D.L., Archinal B.A., Carter M. S., Corbin T.E.,
     Eubanks M.T., Florkowski D.R., Hall D.M., McCarthy D.D., McCulloch P.M.,
     King E.A., Nicolson G., Shaffer D.B.
    
    =1995AJ....110..880J
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ADC_Keywords: Radio sources ; Positional data ; VLBI

Abstract:
    A catalogue is presented based on the radio positions of 436
    extragalactic sources distributed over the entire sky. The positional
    accuracy of the sources is better than 3 milliarcsec (mas) in both
    coordinates, with the majority of the sources having errors better
    than 1mas. This catalogue is based upon a general solution of all
    applicable dual frequency 2.3 and 8.4GHz Mark-III VLBI data available
    through the end of 1993 consisting of 1,015,292 pairs of group delay
    and phase delay rate observations. Details and positions are also
    given for an additional 124 objects that either need further
    observation or are currently unsuitable for the definition of a
    reference frame. The final orientation of the catalogue has been
    obtained by a rotation of the positions into the system of the
    International Earth Rotation Service and is consistent with the FK5
    J2000.0 optical system, within the limits of the link accuracy.

File Summary:
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 FileName    Lrecl    Records   Explanations
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ReadMe          80          .   This file
table4.dat     136        436   Radio positions of sources used to define the
                                reference frame
table5.dat     136        124   Radio positions of candidate and other sources
table6.dat      51         53   Sources observed unsuccessfully
table9.dat     122        614   Supplementary source identification
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Byte-by-byte Description of file: table4.dat table5.dat
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   Bytes Format  Units      Label      Explanations
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       3  I1     ---        Class      Source Classification (1)
  13- 20  A8     ---        Name       Source Name
  28- 29  I2     h          RAh        Right ascension (J2000)
  31- 32  I2     min        RAm        Right ascension (J2000)
  37- 45  F9.6   s          RAs        Right ascension (J2000)
  50- 57  F8.6   s        e_RAs        Right ascension (J2000) Formal Error (2)
      62  A1     ---        DE-        Declination sign
  64- 65  I2     deg        DEd        Declination (J2000)
  67- 68  I2     arcmin     DEm        Declination (J2000)
  73- 80  F8.5   arcsec     DEs        Declination (J2000)
  85- 91  F7.5   arcsec   e_DEs        Declination (J2000) Formal Error (2)
  95-100  F6.3   yr         Mean       Mean Epoch of Observation (Epoch-1900)
 104-109  F6.3   yr         EpFirst    Epoch of First Observation (Epoch-1900)
 113-118  F6.3   yr         EpLast     Epoch of Last Observation (Epoch-1900)
 123-127  I5     ---        EpNexp     Number of experiments in which a source
                                        was observed
 132-136  I5     ---        Nobs       Number of delay/rate observations used
                                       in solution
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Note (1): 1,2-defining; 3-candidate; 4,5-other; 6-not detected
Note (2): The formal errors refer to a position based on all observations of a
           source, which is different from the level of accuracy expected from
           only one observation or experiment. Systematic errors are estimated
           to be at the 0.5mas level.
          The right ascension formal error for 0420-014 was taken from the CTF
           solution because the right ascension of this source was fixed in the
           ICF solution to its a priori value in order to define the equinox.
           Consequently, the right ascension uncertainty of 0420-014 should be
           added in quadrature to the right ascension uncertainties of the
           remaining sources.
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Byte-by-byte Description of file: table6.dat
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   Bytes Format  Units      Label      Explanations
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       3  I1     ---        Class      Source Classification (1)
  13- 20  A8     ---        Name       Source Name
  28- 29  I2     h          RAh        Right ascension (J2000)
  31- 32  I2     min        RAm        Right ascension (J2000)
  34- 37  F4.1   s          RAs        Right ascension (J2000)
      42  A1     ---        DE-        Declination sign
  44- 45  I2     deg        DEd        Declination (J2000)
  47- 48  I2     arcmin     DEm        Declination (J2000)
  50- 51  I2     arcsec     DEs        Declination (J2000)
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Note (1): 1,2-defining; 3-candidate; 4,5-other; 6-not detected
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Byte-by-byte Description of file: table9.dat
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   Bytes Format  Units      Label      Explanations
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   1-  8  A8     ---        Name       Source name
  12- 14  A3     ---        Type       Optical identification (1)
  18- 22  F5.3   ---        z          []? Redshift
  26- 30  F5.2   mag        mv         []? Visual Magnitude
  34- 37  F4.1   Jy         S6cm       []? 6cm (5GHz) Radio flux density
  49- 72  A24    ---        Alt        Alternate name(s)
  74-122  A49    ---        Ref        Reference
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Note (1): QSO = quasar, BSO = blue stellar object, GAL = galaxy,
          LAC = BL Lac object, EF = empty field
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Origin: AAS CD-ROM series, Volume 5, 1995         Lee Brotzman [ADS] 27-Sep-1995
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(End)                                                         [CDS]  10-Jan-1996