Showing papers by "Warrick J. Couch published in 1993"
TL;DR: In this paper, the evolution of galaxies as a function of look-back time is investigated using early-type galaxies in rich cluster environments, and a sample of 180 galaxies selected at near-infrared wavelengths in the fields of 10 rich clusters with 0.5 < z < 0.9.
Abstract: This paper investigates the evolution of galaxies as a function of look-back time, primarily using early-type galaxies in rich cluster environments. We demonstrate that, by selecting distant galaxies in the near-infrared, representative samples containing approximately the same proportion of galaxy classes can be constructed independently of redshift, thus avoiding biases introduced by optical selection criteria. Using this method, we construct a sample of 180 galaxies selected at near-infrared wavelengths in the fields of 10 rich clusters with 0.5 < z < 0.9. Observing and data processing techniques, with infrared arrays yielding the required high-precision photometry of cluster members, are discussed
218 citations
TL;DR: In this article, the angular correlation function of galaxies, w(θ), and its evolution with apparent magnitude at VR ≤ 235 mag were analyzed on a data set containing 116000 galaxies covering almost 4 deg 2 at high galactic latitudes, obtained with the Berkeley f/1 camera on the 39m Anglo-Australian Telescope.
Abstract: We present new results on the angular correlation function of galaxies, w(θ), and its evolution with apparent magnitude at VR ≤ 235 mag The analysis has been carried out on a data set containing 116000 galaxies covering almost 4 deg 2 at high galactic latitudes, obtained with the Berkeley f/1 CCD camera on the 39-m Anglo-Australian Telescope We find that, at scales less than 0°2, w(θ) is well described by a pure power law, w(θ) ∞ θ −070±005 , with no evidence for any systematic change in the value of the power-law index with apparent magnitude limit
44 citations
TL;DR: In this article, radio-quiet QSOs in the redshift range 0.9 < z < 1.5 have been analyzed to search for associations between radio-loud and distant galaxies.
Abstract: Deep (R ) ∼ − 24) radio-quiet QSOs in the redshift range 0.9 < z < 1.5 have been analysed to search for associations between QSOs and faint galaxies. No significant excess of galaxies is found around the QSOs, in marked contrast to previous studies of optically luminous, radio-loud QSOs. This result may reflect real differences between the environments of radio-loud and radio-quiet QSOs at intermediate redshifts. However, optical luminosity effects and the differential effect of gravitational lensing may also play an important role in the observed differences in the cluster environment between these two classes of QSO
15 citations
1 citations