Spectral Evolution of Galaxies

As it was said by one of the participants to this workshop" In our attempts to understand the spectral evolution of galaxies, we are fortunate indeed to have the ability to look back in time and observe galaxies as they were billions of years ago. Perhaos in no other discipline is it possible to gain such a direct view to hJstory. The galaxies we seek to study are remote, their light faint, and thus only recently has it become technicaJlv feasible to sample the spectra of normal luminosity galaxies at lookback times of five billion years or more" .... or, perhaps. even to see galaxies in the process of their formation. or shortly afterwards. This fourth workshop organized by the "Advanced School ot Astronomy was indeed centered on the "Spectral Evolution of Galaxies". on reviewing and discussing the relevant astrophysical processes and on assessing our current ability to model and understand the evolution of stellar populations. Following an opening session dealing with some outstanding questions of galaxy evolution. Session I addressed the specific problems of galaxy and star formation processes. topics of uncertainty and controversy to which IRAS observations may give novel perspectives. The properties of stellar populations in the local group of galaxies formed the basis of Session II. Session III dealt with the fundaments of the theory of spectral and photometrical evolution of stellar populations. and with recent developments in the theory of stellar structure. a necessary step to model and understand galactic evolution.

Inhalt

Introductory Lecture.- Galaxy evolution: some issues and questions.- I. Galaxy and Star Formation Processes.- Towards a theory of galaxy formation.- Physical processes in star formation.- Theoretical and observational evidence for the existence of a single fragmentation law, and galactic evolution.- Star formation tracers in galaxies.- Age and processes of star formation in very young LMC associations.- On the relationship between neutral hydrogen mass, luminosity and color in irregular galaxies.- IZW18 and the search for very metal poor galaxies.- Bolometric luminosity evolution.- Galaxy encounters and the Holmberg effect.- The effects of galaxy-galaxy interactions on nuclear activity.- Galaxies in the infrared.- IRAS far-infrared observations of interacting galaxies.- II. Stellar Populations in the Local Group.- The stellar populations of galaxies in the local group.- M giants in the galactic nuclear bulge.- Age and mass of M giants in the galactic bulge.- The AGB population of nearby galaxies.- M33: radial distributions and a comparison of its global luminosity function with other nearby galaxies.- III. Towards Modelling the Spectral Evolution of Galaxies.- Global properties of stellar populations and the spectral evolution of galaxies.- Advancements in the stellar evolution theory: the role of convective overshooting all across the HR diagram.- Spectral evolution of galaxies.- Spectrophotometric models of galaxies.- Photometric evolution of elliptical galaxies in the color - magnitude diagram.- IV. Empirical Population Synthesis.- Analysis of stellar populations at large lookbacks.- Population synthesis and epochs of star formation in NGC 1316 (Fornax A).- Far-UV stellar populations of SO galaxies.- The UV energy distribution of elliptical galaxies.- UV spectra of normal ellipticals.- V. Galaxies at Large Lookback Times.- Studies of cluster galaxies at large lookback times.- Observational tests for galaxy evolution.- Colors of 3CR and first-ranked high redshift galaxies.- Evolution of disk galaxies in high-redshift clusters.- Quests for primeval galaxies: a review of optical surveys.- New observations of galaxy number counts.- VI. Chemical Evolution of Galaxies and Miscellanea.- The chemical evolution of galaxies.- Nitrogen and oxygen evolution in nearby spiral galaxies.- Effects of metal-dependent stellar models on the yield of nitrogen.- Surface brightness distributions in two edge-on spiral galaxies.