No abstract

SummaryThis paper gives details of 397 radio sources between declina.tions + 20 0 and +27 0 which were compiled from a finding survey made at 635 MHz with the 210 ft reflector at the Australian National Radio Astronomy Observatory, Parkes, N.S.W.The survey covers an area of 0·703 steradian but is incomplete in two regions within ± 100 of the galactic equator. Additional measurements of flux densities and positions were made at 1410 and 2650 MHz. Some discussions on spectra, source counts, and source identifications are included, and a comparison is made between this survey and other published oatalogues oovering the same region. I. INTRODUOTIONThis paper is the fifth seotion of a survey for radio souroes being made with the 210 ft radio telescope at the Australian National Radio Astronomy Observatory, Parkes, N.S.W. The earlier parts of the survey have already been published and oover the declination zones 0° to +20° ), 0° to -20° (Shimmins et al. 1966), -20° to _60° (Bolton, Gardner, and Maokey 1964, and _60° to _90° (Prioe and Milne 1965). The present paper oovers the remaining deolination zone that is visible with the Parkes telesoope, +20° to +27°, and is oomplete except for two areas within ±10 0 of the galactio equator. The oatalogue oontains 397 souroes within O· 703 steradian, 341 of these souroes being outside the region ± 10° of the galaotio equator (effeotive area 0·606 steradian). The oatalogue is thought to be substantially oomplete down to a flux density of 1·5 f.u.t at 635 MHz outside the galaotio plane region but oontains some weaker souroes down to 0·8 f.u.The observations differ from those of the earlier seotions of the oatalogue in that the finding survey was done at a frequenoy of 635 MHz. Positions and flux densities were subsequently measured at 1410 and 2650 MHz.The estimated r.m.s. errors in position and the date of measurement are given for eaoh souroe in the oatalogue.

A catalogue of 34S radio sources is presented, covering right ascensions O&h 00'" to 17 h OO'" and 19 h 30'" to 06h30'" between declinations _4° and -30°. The regions omitted are within -10° of the galactic plane. The catalogue was compiled from a 'fast' finding survey at 2700 MHz aimed at detecting sources stronger than o· 5 Jy. Subsequent measurements of flux density and position were made on all the sources which were not in the Parkes 40S MHz catalogue, and on some sources in the Parkes 40S MHz catalogue for which only data of low accuracy were available. Positions of the sources were determined to an accuracy of 7" arc r.m.s. in both coordinates. Flux densities for all sources were also measured at 5009 MHz. Identifications are suggested for 50 galaxies, 100 quasi-stellar objects and 4 planetary nebulae.

SummarySeventy-four identifications have been made from inspection of the 48 in. Sky Survey prints in positions of 150 sources measured with the 210 ft telescope. Thirty-seven of the identified sources are galaxies and 37 possible quasi-stellar objects. In 26 cases previously suggested identifications are confirmed. Finding charts are given for the remainder.

Accurate flux densities at 8·87 GHz have been determined with the Parkes 64 m telescope for 195 radio sources, using an on-off integration method. The sources were selected from the Parkes 408 and 2700 MHz catalogues as those having estimated flux densities at 8·87 GHz greater than O' 5 f.u. and relatively small angular sizes. Eighty of the selected sources are identified with QSO's, 40 with galaxies, and one with an HII region, while 74 have not been identified. The estimated accuracy of the flux density is ±0·02 f.u. (r.m.s.) due to system noise and ±3'5% due to other causes. A list of known or newly suspected radio variables in the sample is given.