In the last decade much work has been carried out in the development and use of the 44' objective prism of the UK Schmidt Telescope Unit (UKSTU) for the purpose of deriving redshifts of galaxies.
The primary intention has been to obtain large numbers of moderately accurate redshifts for faint galaxies in order to probe the large scale spatial distribution of galaxies. The attainable accuracy with the 44' prism is such that supercluster sized structures can be resolved.
In 1982 a new prism with a refracting angle of 13 2 1 was commissioned. On its own, or in combination with the old prism, this new instrument results in higher dispersion spectra though at brighter limiting magnitude.
This thesis discusses the modification of existing methods and the development of new methods for the derivation of galaxy redshifts from higher dispersion spectra.
The advantages and disadvantages of new versus old are discussed. Magnitude and morphological range of suitable samples are presented.
It is found that the overall accuracy of redshifts from the dispersion 2 prism combination (1240A/mm at HIT) is +/-1150Km/s and that the limiting magnitude is 16.5. The range of later morphological types that are suitable for measurement is increased compared with results from the 44' prism. The approximate redshift range is from zero to z=0.1.
Observations have been made of a prominent cluster in the region of the Coma supercluster. Prism derived redshifts for most of the galaxies in this cluster show that it is at a similar redshift to the Coma supercluster, though plates of the intervening region will be needed to establish a physical connection with the supercluster. Prism plates have been taken of a region south of the supercluster and whilst there is no evidence of structure at the redshift of the supercluster, a background cluster has been discovered.