[en] Most of the galaxy redshifts currently available in the literature have been measured from photographic spectra and are generally based on subjective estimates of the position of the narrow absorption features. In using only the few prominent absorption lines, most of the light from the galaxy is discarded. With the advent of digital linear-response detectors it is possible to obtain accurate and objective redshifts by cross-correlating all or part of the galaxy spectrum with a template galaxy of known redshift. The problem of identifying and measuring wavelengths for blended features is avoided

[en] A preliminary estimate of the maximum neutrino content of elliptical galaxies is made. The method is to find a plausible means of associating a degenerate neutrino polytrope with the structure of an elliptical galaxy. The polytropic model is likely to be accurate for the biggest galaxies, as these have a large neutrino content, but since the baryons are more centrally concentrated than the neutrinos in the smaller galaxies, the approach described underestimates their maximum neutrino content

[en] At what stage of stellar evolution the grossly non-solar abundance phase occurs, whether all stars pass through this stage and whether the phase is significant in the overall picture of galactic nucleosynthesis are questions considered for carbon stars. Observations discussed include those made of intermediate-age clusters in the Magellanic Clouds (NGC 419 and NGC 1846) and the galactic clusters NGC 2477 and NGC 2660. Data is provided on metal abundances, ages, turn-off masses and carbon star numbers. Observations which are not predicted in present dredge-up calculations for carbon star production include enhanced Zr (S process) in the brightest M star in NGC 1846 and the high C-13/C-12 ratio in two of the 13 carbon stars in NGC 419

[en] In 1977 a near infrared survey of the southern Milky Way was commenced with the SRC 1.2m Schmidt telescope at Siding Spring. It consisted of 151 survey fields which have centres within 10 deg. of the galactic plane and negative declinations. A further 12 fields have subsequently been added to the survey to permit coverage of the Large and Small Magellanic Clouds

[en] Comparison of HCO⁺ contours with contours of 69 μm and 6 cm continuum emission indicates a close relationship between molecules, dust and ionized gas in the overall diffuse components and in the more compact regions of NGC 6334. Examination of the HCO⁺ velocity pattern and comparison with H₂CO data suggest that one of the compact regions is located behind the ionized gas. Because of this the velocity pattern is compatible with an interpretation as an expanding shell of dense molecular complexes containing newly formed stars and other associated compact objects

[en] A common test for hydrodynamic calculations is the problem in which an isothermal, spherical cloud with the Sun's mass is given a cos(2 phi) density perturbation and the ensuing evolution studied. Results from finite difference calculations differ from those where the particle method SPH is used. Instead of the maximum density rising continually throughout the evolution in the SPH method a maximum density is achieved. A second difference concerns calculations showing coalescence of fragments. The calculations described use a refined SPH method with improved resolution

[en] These preliminary results show that the artificial viscosity used with the SPH scheme models shocks in high Mach number cloud collisions effectively. Results show that cloud-cloud collisions tend to disrupt and disperse the clouds rather than result in coalescence

[en] The dynamical collapse of a rotating body with mass less than Chandrasekhar's limiting mass, from white dwarf densities to neutron star densities, is examined. Provided the general relativistic effects are limited to a small perturbation, the post-Newtonion equations of Chandrasekhar should adequately model the collapse

[en] Previous studies have suggested that a freshly formed white dwarf star of several solar masses would, if slowly rotating, collapse to form a neutron star pancake which would become unstable and eventually produce several, possibly colliding, neutron stars. If the star is rapidly contracting the theoretical stability studies become invalid, and numerical experiments are required to determine whether or not an instability occurs. As a preliminary to a full general relativistic study of the collapse the authors describe experiments based on Newtonian equations of motion

[en] In brightness, shape, size, sense of polarization, dispersion of height with observing frequency, and increase of size with decreasing observing frequency - i.e. in almost all characteristics other than height and movement - most moving Type 4 radio sources closely resemble common solar radio sources which are universally believed to arise through Langmuir-wave conversion. Many of the characteristics of moving Type 4 radio sources, particularly perhaps height-dispersion, sense of polarization, and high degree of polarization, are more easily explained in terms of Langmuir-wave conversion than in terms of incoherent gyrosynchrotron emission