Structural and Photometric Properties of Extragalactic Stellar Spheroids

After an overview of the science of galaxy morphology, a new classification for galactic form, based upon the Yerkes system, is presented. This classification scheme is then applied to the study of the role of environment in determining the nature of galaxy populations. By examining the distribution of galaxy types in 11 clusters and groups a number of new facts are brought to light: The relation between spiral fraction and local density found by Dressler is confirmed. However, the elliptical galaxy fraction, in groups they contain at least one elliptical, is found to be independent of density. The dwarf galaxy populations in and out of the cluster environment are shown to be very different. Two distinct families of low luminosity spheroids are identified, and their properties compared.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Astronomy

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Wirth, Allan

• Physics, Astronomy and Astrophysics

Identifier

(UMI)AAI8303025

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/70661