We present the Extreme-Horizon (EH) cosmological simulation: EH models galaxy formation with stellar and AGN feedback and uses a very high resolution in the intergalactic and circumgalactic medium. The high resolution in low-density regions results in smaller-size massive galaxies at redshift z=2, in better agreement with observations compared to other simulations. This results from the improved modeling of cold gas flows accreting onto galaxies. Besides, the EH simulation forms a population of particularly compact galaxies with stellar masses of 1010−11\,M\sun that are reminiscent of observed ultracompact galaxies at z≃2. These objects form mainly through repeated major mergers of low-mass progenitors, independently of baryonic feedback mechanisms. This formation process can be missed in simulations using a too low resolution in low-density intergalactic regions.
@article{arxiv.2007.04624,
title = {Formation of compact galaxies in the Extreme-Horizon simulation},
author = {Solène Chabanier and Frédéric Bournaud and Yohan Dubois and Sandrine Codis and Damien Chapon and David Elbaz and Christophe Pichon and Olivier Bressand and Julien Devriendt and Raphael Gavazzi and Katarina Kraljic and Taysun Kimm and Clotilde Laigle and Jean-Baptiste Lekien and Garreth Martin and Nathalie Palanque-Delabrouille and Sébastien Peirani and Pierre-Franck Piserchia and Adrianne Slyz and Maxime Trebitsch and Christophe Yèche},
journal= {arXiv preprint arXiv:2007.04624},
year = {2020}
}
Comments
Submitted to A&A Link to a projection of the simulation at z = 2 in high definition: http://www.galactica-simulations.eu/EH_L50/index.html