The Nature of High [OIII]/[CII] Galaxies in the Epoch of Reionization: Low Carbon Abundance and a Top-Heavy IMF?
If you have a question about this talk, please contact Martin Haehnelt.
ALMA observations of z>6 galaxies have revealed abnormally high [OIII]/[CII] ratios and [CII] deficits compared to local galaxies. The origin of this behaviour is unknown. Numerous solutions have been proposed including differences in C and O abundance ratios, observational bias, and differences in ISM properties, including ionisation parameter, gas density, or photodissociation region (PDR) covering fraction. In order to elucidate the underlying physics that drives this high-redshift phenomenon, I will introduce SPHINX20 , a new state-of-the-art, cosmological radiation-hydrodynamics simulation, that resolves detailed ISM properties of thousands of galaxies in the epoch of reionization and discuss the physics that drives high [OIII]/[CII] ratios.
This talk is part of the Institute of Astronomy Galaxies Discussion Group series