The morphology and absolute diameters of galaxies

This is the first time to the author's knowledge that a catalogue of galaxy photographs has been prepared on a uniform physical scale. Of the many interesting aspects which result from such an investigation, we mention here the fundamentally new appreciation both of the diversity of spiral arm texture, and in the range of the intrinsic diameters of galaxies, particularly the spirals. Small, high surface brightness spiral galaxies form an important subgroup; these present a saturated or predominantly saturated image on the SRC IIIa-J Survey. An intercomparison of their appearance on the J-film copies and those of the "Quick Blue" Survey shows an inner morphology often indicative of substantial differential rotation effects. One of our galaxies in the sample shows significant signs of warping; the spiral has no bright, close companions. Also of note are faint, featureless outer envelopes in some of the spirals, and galaxies with faint outer spiral arms whose pitch angles are significantly different from those of the central inner region. Further results are discussed in chapter 3 onwards. A by-product of this investigation is the identification of the largest known (type b) barred spiral.

Grantor dc:publisher.institution

Department of Astronomy

Year dc:date.issued

1980

Author dc:creator

• Block, David Lazar

Advisor dc:contributor.advisor

• Fairall, Anthony Patrick

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/12539

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/12539