›Mapping oxygen in the Universe
Oxygen is the most abundant heavy element in the Universe. It is the most direct testimony of the history of star formation. The oxygen abundance is easily measured up to high redshifts through emission lines produced in the interstellar medium of star forming galaxies and through absorption lines observed on the linesight of bright, high redshift sources. Recently, there has been a large amount of studies on the determination of oxygen abundances in the local Universe, both in young and old stars, which have brought interesting constraints but also many questions. Among others, the oxygen abundance in the Sun is still lively debated. Studies of oxygen abundances from absorption lines in the local ISM as well as from emission lines from planetary nebulae and HII regions in Galactic and extragalactic Milky Way have also developed significantly.
It is time to confront all these determinations and discuss thoroughly the biases and uncertainties to provide a firm ground for theories and models of chemical evolution of galaxies.
This workshop would then not be principally one of "results" but rather one of "confrontations and discussions".
- Oxygen atomic data and modelling procedures in nebulae and stars
- Methods of oxygen abundance determination
- Oxygen in stellar atmospheres and the problem of mixing
- Oxygen in the interstellar medium and the problem of dust depletion
- Oxygen in ionized nebulae and the abundance discrepancy problem
- Comparison of oxygen abundances in the same site from various indicators (solar neighborhood, nearby galaxies)
- The oxygen abundance gradient and dispersion in the Milky Way and spiral galaxies
- The global oxygen abundance in spiral galaxies
- Proxies for oxygen abundances in elliptical galaxies
- Oxygen as an observational constraint for chemical evolution studies