(Abridged) We describe the results of the highest-resolution radio observations yet made of four relic radio sources in the Abell clusters A13, A85, A133 and A4038. Our VLA images at 1.4 GHz with 4" resolution show a remarkable variety of fine structure in the form of spectacular arcs, wisps, plumes and loops. Their integrated radio flux densities fall very rapidly with frequency, with power-law slopes between 2.1 and 4.4 near 1.4 GHz The relics possess linear polarization levels ranging between 2.3 % (A133) and 35 % (A85); the higher polarization fractions imply a highly ordered magnetic field in the fine structure and low differential Faraday rotation in the intervening cluster gas. The optical identification of host galaxies remains problematic. In A85, A133 and A4038 the travel times for the brightest cluster galaxies are significantly longer than the modeled ages of the relics and nearby bright ellipticals provide a better match. Excess X-ray emission in the 0.5 keV-to-2 keV band was found near the relics in A85 and A133. The surface brightness was too high to be attributed to the inverse-Compton mechanism alone. We found excellent fits to the broad-band radio spectra using the anisotropic (KGKP) model of spectral ageing, and we have extended the model to include diffusion of particles between regions of different field strength (the Murgia-JP, or MJP, model). The steep radio spectra imply ages for the relics of ~ 10^8 yr, at the start of which period their radio luminosities would have been ~ 10^25 W/Hz at 1.4 GHz.Comment: 43 pages, 13 figures, AJ, Sep 2001 (accepted

EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms ,10 mJy/beam) radio continuum survey of the entire Southern sky at 1.3 GHz, extending as far North as þ308 declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z , 1, powerful starbursts to even greater redshifts, and active galactic nuclei to the edge of the visible Universe. It will undoubtedly discover new classes of object. This paper defines the science goals and parameters of the survey, and describes the development of techniques necessary to maximise the science return from EMU.

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I present a final updated and recalibrated list of sources that were observed with the Culgoora circular array in the interval 1970~1984. The present list contains all the sources that were contained in the Culgoora-1, 2, 3 Lists plus additional sources resulting from a survey of 353 Abell clusters of galaxies. The electronic version of the Culgoora List, with appropriate documentation, is available from the Einstein On-Line Service.

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SummaryA catalogue has been prepared of the radio sources observed between declinations _20 0 and _50 0 , using the Sydney cross-type radio telescope at a wavelength of 3·5 m ; a total of 892 sources is listed. This supplements an earlier catalogue in the declination zone + 10° to _20°. In addition to the positions and intensities of the sources, angular sizes of 50 of the strongest are given: several are found to have a size less than 15" arc. As before, identifications with bright optical objects have been sought, and a number of galaxies of apparently abnormal radio emission listed. Statistical analyses of the distribution of the radio sources give results very similar to those obtained using the earlier catalogue. \Vithin the uncertainty in the data, the distribution appears uniform in depth and there is a siguificantly greater number of sources of large apparent size than expected from chance blending effects.

The Culgoora radioheliograph operating at 80 MHz has been used to observe 999 radio sources selected from published catalogues and distributed over the declination range -48� to +35�. The Culgoora-l list contains measurements with 3' . 7 arc resolution of positions, flux densities, and angular sizes of 777 sources, while upper limits to the flux densities of 222 undetected sources are given in a separate list. Success rates for the detection of various classes of radio source at 80 MHz are listed and discussed. Comparisons are made between the Culgoora flux densities and those given in other catalogues, and it is shown that unresolved sources in the earlier low-resolution measurements near 80 MHz cause the flux density to be systematically overestimated.