RSAA Colloquia / Seminars / Feast-of-Facts: Thursday, 06 October 2016, 11:00-12:00; Duffield Lecture Theatre

Elisabete da Cunha

"Modelling the spectral energy distributions of high-redshift galaxies: recent progress and future challenges"

Multi-wavelength observations spanning the full ultraviolet to radio spectral range are becoming available not only for local galaxies, but also for samples of increasingly high redshift galaxies, thanks to deep observations with e.g. both ground- and space-based observatories. In order to understand these observations in the context of galaxy evolution theories, we use spectral energy distribution (SED) models that translate the observed light into key physical properties such as stellar mass, star formation rate, metallicity, and dust content. While these models have been extensively calibrated and applied to local galaxy samples, they are now starting to be used to understand galaxies in the young Universe. In this talk I will review the main ingredients of SED models and I will describe recent and ongoing developments. I will focus on specifically on: (i) recent updates on the spectral evolution of young stellar populations; (ii) self-consistent modelling of the nebular emission of galaxies, and how this affects the broad-band SEDs; (iii) challenges in parameterizing the star formation histories of galaxies, and why they matter; (iv) progress in modelling the contamination by active galactic nuclei (AGN); and (v) how to account for ‘cosmological effects’ when modelling galaxy SEDs at high redshifts.