Proc. Astr. Soc. Australia, 10, 140, (1992)

A Catalogue of 'Southern' Radio Sources with Accurate Positions

Graeme L. White

Abstract: A list of 901 radio sources with positional accuracies better than 0.5 arcseconds has been prepared from seventeen lists of radio source positions found in the literature. This compilation includes all such sources south of declination +48 deg (the northern declination limit of the Compact Array of the Australia Telescope National Facility). Where available, optical identifications, optical magnitudes and redshifts are given as well as total-power flux densities.

1. Introduction

2. The Catalogue

Of the 901 radio sources, 396 (44 %) are north of the Celestial Equator while only 101 (11 %) are in the far southern sky south of declination -45 deg; again it is noted that there are few published accurate positions in this far southern region. The compilation contains 530 Quasars, 115 galaxies, 45 BL Lacertae type objects and 55 empty optical fields. No optical identifications are available for a further 155 radio sources.

The majority of the positions catalogued have been determined by either observations with the VLA or VLBI observations. Positions determined using VLBI techniques are biased towards the compact component of the source and these positions may not be consistent with positions found using other instruments with lower resolution that determine the centroid of sources with extended structure. This will be especially so for radio galaxies of low redshift. The accuracy of the individual positions is indicated by a code which has been modelled on that adopted for the VLA calibration list (see below). There are 137 sources for which the original catalogued position is more accurate than 0.02", 33 in the range 0.02 to 0.05" and 335 in the range 0.05 to 0.15". The largest group of sources, 396 or 44 % of the total, have less accurate positions, with rms uncertainties >0.15". For the sources south of dec -45 deg, 89 % fall in this category of lower accuracy positions.

The format of the catalogue is as follows: Column 1: Source name based on the B1950.0 position. Column 2 The accuracy of the positions in columns (3) to (6). For convenience, the code used is the same as that used in the VLA calibration lists: A --Position more accurate than 0.02" B --Position accuracy in the range 0.02 to 0.05" C --Position accuracy in the range 0.05 to 0.15" T --Position less accurate than 0.15"

Columns 3,4: The mean position of the radio source for the equator and equinox of B1950.0. The positions here are directly from the literature for sources that were catalogued in B1950.0 coordinates. For sources that were catalogued with J2000.0 positions the B1950.0 positions were precessed using the STARLINK software COCO which is based on the algorithms of Smith et al. (1989) and Yallop et al. (1989). Estimated epochs of observations were used unless they were specified in the literature. For radio sources where many positions were available in the literature, the position that was determined using the instrument that most closely resembles the CA of the ATNF is given in columns 3, 4 and 5, 6. This position will be the most useful for calibration of the CA. Often this was the position from the VLA calibration list. The number of significant figures ascribed to the position indicates the catalogued accuracy of that source.

Columns 5,6: The mean position of the radio source for the equator and equinox of J2000.0. The positions here are directly from the literature for sources that were catalogued in J2000.0 coordinates. For sources that were catalogued with B1950.0 positions the J2000.0 positions were computed using the STARLINK software COCO. Other details are as for columns 3 and 4.

Column 7 The optical identification of the radio source taken from the Parkes catalogue (PKSCAT90--Parkes Catalogue, 1990, ATNF) or the compilation by Veron-Cetty and Veron (1991). The abbreviations used are:

  *  = Star (introduced in the present electronic version by H.A., one case)
  Q  = Quasar (QSO)
  G  = Galaxy
  EF = Empty or blank optical field
  BL = BL Lacertae type object
  ?  = No optical identification suggested in the literature

Columns 10-12 The total flux density at observing frequencies of 408, 2700 and 5000 MHz respectively. These have been adopted from the Parkes Catalogue (PKSCAT90 -- Parkes Catalogue, 1990, ATNF), the Molonglo Reference Catalogue (MRC, Large et al. 1981), the VLA calibration list or from Veron-Cetty & Veron 1991. Flux densities are given here to allow estimation of the strength of the source as seen with a single dish such as the Parkes Radio Telescope. Many of these sources are compact in angular size and will be radio variables. The flux densities given are not for the flux density calibration of an interferometer. Column 13 Cross references. Most of these sources have more than one position in the literature and the positions given have been taken from the first references in this column. The following abbreviations have been used:

A --Argue, A.N., et al. (1984)
C --Condon, J.J., (pers comm)
D --Morabito, D.D., et al. (1986)
F --Fanselow, J.L., et al. (1884)
H --Harvey, G.R., et al., 1992
I --International Earth Rotation Service (IERS) Tech. Note 2 (1989)
J --Jauncey, D.L., et al. (1989a)
L --Lestrade, J-F., et al (1988)
M --Ma, C., et al. (1986)
N --Hunstead, R.W., 1989 (pers comm)
P --Perley, R.A. (1982)
R --Robertson, D.S., et al. (1986)
S --Sovers, O.J., et al. (1988)
U --Ulvestad, J., et al. (1981)
V --The VLA calibration list (per comm Dr R. Perley of the VLA staff)
W --White, G.L., et al. (1989)
Y --Jauncey, D.L., et al. (1989b)

Acknowledgements

Argue, A.N., et al., 1984, A&A, 130, 191.
Fanselow, J.L., Sovers, O.J., Thomas, J.B., Purcell, G.H., Cohen, E.J., Rogstad, D.H., Skjerve, L.J. and Spitzmesser, D.J., 1984, AJ, 89, 987.
Harvey, B.R., Jauncey, D.L., White, G.L., Nothnagel, A., Nicolson, G.D., Reynolds, J.E., Morabito, D.D. and Bartel, N., 1992, AJ, 103, 229.
Jauncey, D.L., et al., 1989a, AJ, 98, 49.
Jauncey, D.L., Savage, A., Morabito, D.D., Preston, R.A., Nicolson, G.D. and Tzioumis, A.K., 1989b, AJ, 98, 54.
Large, M.l., Mills, B.Y., Little, A.G., Crawford, D.F. and Sutton, J.M., 1981, MNRAS, 194, 693.
Lestrade, J-F., Neill, A.E, Preston, R.A. and Mutel, R.L., 1988, AJ, 96, 1746.
Ma, C., et al., 1986, AJ, 92, 1020.
Morabito, D.D., Preston, R.A., Linfield, R.P., Slade, M.A. and Jauncey, D.L. 1986, AJ, 92, 546.
Perley, R.A., 1982, AJ, 87, 859.
Robertson, D.S., Fallon, F.W. and Carter, W.E.,1986, AJ, 91, 1456.
Sovers, O.J., Edwards, C.D., Jacobs, C.S., Lanyi, G.E., Liewer, K.M. and Treuhaft, R.N., 1988, AJ, 95, 1647.
Smith, C.A., Kaplan, G.H., Hughes, J.A., Seidelmann, P.K., Yallop, B.D. and Hohenkerk, C.Y., 1989, AJ, 97, 265.
Ulvestad, J., Johnston, K., Perley, R. and Fomalont, E., 1981, AJ, 86, 1010.
Veron-Cetty, M.P. and Veron, P., 1991, European Southern Observatory Scientific Report No 10.
White, G.L., Lestrade, J-F., Jauncey, D.L., Phillips, R.B., Preston, R.A. and Reynolds, J.E., 1989, AJ, 99, 405.
Yallop, B.D., Hohenkerk, C.Y., Smith, C.A., Kaplan, G.H., Hughes, J.A. and Seidelmann, P.K., 1989, AJ, 97, 274.