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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