Showing papers by "Edwin A. Valentijn published in 1985"
TL;DR: In this paper, the relative velocities of the components in 17 multiple-nucleus galaxies have been measured and the authors find that the distribution of velocity differences is consistent with random sampling from a Gaussian with a dispersion of ≡800 km s-1, typical of that found in rich clusters.
Abstract: Relative velocities of the components in 17 multiple-nucleus galaxies have been measured. Combining these results with previously published data, the authors find that the distribution of velocity differences is consistent with random sampling from a Gaussian with a dispersion of ≡800 km s-1, typical of that found in rich clusters. These results are compatible with Merritt's recent suggestion that the majority of the secondary components in multiple-nucleus systems are not bound to the central galaxy and will not merge on a dynamical time-scale.
9 citations
Journal Article•
TL;DR: In this article, the radial color distributions obtained for the galaxy A496 cD indicate that while the halo becomes bluer at increasing radii in the B-V, it becomes redder in the visual-IR colors.
Abstract: J, H, and K radial color distributions obtained for the galaxy A496 cD indicate that while the halo becomes bluer at increasing radii in the B-V, it becomes redder in the visual-IR colors. The combined visual-IR data lead to a unique model for both the main sequence and giant stars in which the main sequence is characterized by a radial increase of an upper mass cutoff, and the giant population is dominated by M4-5III giants. Interpretation of these data in terms of metallicity gradients implies a young population in the halo, while the radial mass cutoff increase, together with the increasing fraction of giant stars, contradicts an aging effect as the reason for the mass cutoff. Several critical predictions of the Valentijn (1983) model, which invokes ongoing star formation out of accreted X-ray gas, are fulfilled.
1 citations
01 Jan 1985
TL;DR: An ongoing photometric survey of 16,000 galaxies on ESO red and blue plates is described in this article, where the galaxies of the ESO/Uppsala catalog are being PDS scanned, and the results are combined with existing photometry and supplementary observational data obtained at the 1m ESO telescope to form a catalog for paper, magnetic-tape, and possibly video-disk publication.
Abstract: An ongoing photometric survey of 16,000 galaxies on ESO red and blue plates is described. The galaxies of the ESO/Uppsala Catalog (Lauberts, 1982) are being PDS scanned, and the results are combined with existing photometry and supplementary observational data obtained at the 1-m ESO telescope to form a catalog for paper, magnetic-tape, and possibly video-disk publication. Details of the plate digitization, photometric calibration, and automatic parameter extraction are discussed, and a flow chart of the extraction operation and graphs of sample data are provided.
1 citations