Affiliation: University of Geneva

Contribution: Oral

Title: Extreme, peculiar, and normal star-forming galaxies at high-z: new discoveries and insights on early galaxies

Abstract: As JWST pushes the limits, astronomers seem to discover galaxies with unusual, extreme, or peculiar properties: this includes strong emission line galaxies, peculiar Balmer line ratios, very UV-bright galaxies, the recently discovered “N-emitters” and others. These discoveries question some of our previous knowledge or potentially even pose more fundamental problems e.g. to our standard cosmological model. In this context, I will highlight recent results and new discoveries of extreme emission line galaxies, the physical properties of their stellar populations and ISM, including detailed abundance patterns, and discuss how these compare to ‘normal’ galaxies at high-redshifts. I will in particular present insights on the N-emitters, low-metallicity galaxies with very high (super-solar) N/O abundances and other abundance ratios which are basically unseen of and unexplained by normal chemical evolution. I will discuss different scenarios which have been proposed to explain these peculiar objects, and attempt to distinguish and test them. Finally I will show that these objects may open new windows on supermassive stars, the formation of globular clusters, and/or supermassive black holes exciting objects and phenomena close to the edge of the Universe.

This contribution can be found here (pdf).