Cake Talk by Yuxiang Qin from University of Melbourne

We are studying ten recently discovered JWST candidates at z>~12, two of which have spectroscopic confirmation, using the Meraxes semi-analytic galaxy formation model. We applied the model to a cosmological simulation with effectively a trillion particles to resolve every atomic-cooling galaxy at z<=20 in a volume of >300cMpc side length. We varied model parameters to reproduce the observed UV luminosity function up to z~13 in our fiducial outputs, aiming for a statistically representative, modelled, high-redshift galaxy catalogue.

Using the forward-modelled JWST photometry, we identified hundreds of galaxies in our fiducial model that resemble the confirmed JWST galaxies and I will present summary of their properties in this talk. For the remaining bright candidates, although challenging, we still successfully identified high-redshift analogues for candidates at z ~13 and I will present some of their possible evolutionary paths during this talk. To reproduce the z>~16 JWST candidates, I will show that the model requires maximized efficiencies to form stars with no feedback regulation, suggesting galaxy formation in these first galaxies could differ significantly from their lower-redshift counterparts. I will also present dusty or quiescent galaxies at z~5 that share similar SEDs as these JWST candidates and compare their formation histories against the high-redshift analogues.