Related papers: The History of Galaxies and Galaxy Number Counts
To understand the evolution of galaxies, we need to know as accurately as possible how many galaxies were present in the Universe at different epochs. Galaxies in the young Universe have hitherto mainly been identified using their expected…
Massive galaxies, such as nearby ellipticals, have relatively low number densities, yet they host the majority of the stellar mass in the universe. Understanding their origin is a central problem of galaxy formation. Age dating of stellar…
We reconstruct the history of the cosmic star formation in the universe by means of detailed chemical evolution models for galaxies of different morphological types. We consider a picture of coeval, non-interacting evolving galaxies where…
Bulges are a major galaxy component in the nearby universe, and are one of the primary features that differentiates and defines galaxies. The origin of bulges can be directly probed in part by examining distant galaxies to search for high…
The excess numbers of blue galaxies at faint magnitudes are a long-standing cosmological puzzle. We present new number-magnitude counts as a function of galactic morphology from the first deep fields of the Cycle 4 Hubble Space Telescope…
Sensitive optical surveys have revealed a large population of `faint blue galaxies' which are believed to be young galaxies, observed close to their time of formation. But there has been considerable uncertainty regarding the epochs at…
The complex problem of when and how galaxies formed has not until recently been susceptible of direct attack. It has been known for some time that the excessive number of blue galaxies counted at faint magnitudes implies that a considerable…
Accurate synthetic models of stellar populations are constructed and used in evolutionary models of stellar populations in forming galaxies. Following their formation, the late type galaxies are assumed to follow the Schmidt law for star…
We use new models of stellar population synthesis to estimate the fraction of stars formed during the last major bursts of star formation in E/S0 galaxies in low-redshift clusters ($z\simlt0.4$) from the spectral signatures of…
This talk investigates the formation of early-type galaxies from a deliberately observational view point. I begin by reviewing the conclusions that can be reached by comparing the detailed properties of galaxies in present-day clusters,…
We have constructed a family of simple models for spiral galaxy evolution to allow us to investigate observational trends in star formation history with galaxy parameters. The models are used to generate broad band colours from which ages…
A constant age population of blue galaxies, postulated in the model of Gronwall & Koo (1995), seems to provide an attractive explanation of the excess of very blue galaxies in the deep galaxy counts. Such a population may be generated by a…
It is an obvious statement that all the galaxies we see today in and around our Local Group have been forming and evolving for a significant fraction of the age of the Universe. It is not a great leap of logic to further state that the…
Several conclusions have been reached over the last few years concerning high-redshift galaxies: (1) The excess of faint blue galaxies is due to dwarf galaxies. (2) Star formation peaks at redshifts z ~1-2. (3) It appears to occur piecemeal…
Many aspects concerning the formation of spiral and disc galaxies remain unresolved, despite their discovery and detailed study over the past $150$ years. As such, we present the results of an observational search for proto-spiral galaxies…
A large deep and nearly complete B<24.5 redshift sample is used to measure the change in distribution function of the stellar mass production rate in individual galaxies with redshift. The evolution of the star formation rate distribution…
Massive, quiescent galaxies at high redshift have been found to be considerably more compact than galaxies of similar mass in the local universe. How these compact galaxies formed has yet to be determined, though several progenitor…
The physical properties of the faint blue galaxy population are reviewed in the context of observational progress made via deep spectroscopic surveys and Hubble Space Telescope imaging of field galaxies at various limits, and theoretical…
Early-type galaxies are considered to be the end-products of massive galaxy formation. Optical spectroscopic studies reveal that massive early-type galaxies formed the bulk of their stars over short timescales (1<Gyr) and at high redshift…
Star formation history shows a gradual decline since the last 8-9 Gyr (z=1). The bulk of present-day stellar mass and metal content was formed at redshifts lower than 2-3, which is consistent with a hierarchical scenario of galaxy…