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

Class Source Classification number=1 1,2-defining; 3-candidate; 4,5-other; 6-not detected --- Name Source Name --- RAh Right ascension (J2000) h RAm Right ascension (J2000) min RAs Right ascension (J2000) s e_RAs Right ascension (J2000) Formal Error number=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. s DE- Declination sign --- DEd Declination (J2000) deg DEm Declination (J2000) arcmin DEs Declination (J2000) arcsec e_DEs Declination (J2000) Formal Error number=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. arcsec Mean Mean Epoch of Observation (Epoch-1900) yr EpFirst Epoch of First Observation (Epoch-1900) yr EpLast Epoch of Last Observation (Epoch-1900) yr EpNexp Number of experiments in which a source was observed --- Nobs Number of delay/rate observations used in solution --- Class Source Classification number=1 1,2-defining; 3-candidate; 4,5-other; 6-not detected --- Name Source Name --- RAh Right ascension (J2000) h RAm Right ascension (J2000) min RAs Right ascension (J2000) s DE- Declination sign --- DEd Declination (J2000) deg DEm Declination (J2000) arcmin DEs Declination (J2000) arcsec Name Source name --- Type Optical identification number=1 QSO = quasar, BSO = blue stellar object, GAL = galaxy, LAC = BL Lac object, EF = empty field --- z Redshift --- mv Visual Magnitude mag S6cm 6cm (5GHz) Radio flux density Jy Alt Alternate name(s) --- Ref Reference --- CDS 1996Jan10AAS CD-ROM series, Volume 5, 1995 Lee Brotzman [ADS] 27-Sep-1995 J_AJ_110_880.xml