Formation of elongated galaxies with low masses at high redshift
Abstract
We report the identification of elongated (triaxial or prolate) galaxies in cosmological simulations at . These are preferentially low-mass galaxies (), residing in dark-matter (DM) haloes with strongly elongated inner parts, a common feature of high-redshift DM haloes in the CDM cosmology. Feedback slows formation of stars at the centres of these halos, so that a dominant and prolate DM distribution gives rise to galaxies elongated along the DM major axis. As galaxies grow in stellar mass, stars dominate the total mass within the galaxy half-mass radius, making stars and DM rounder and more oblate. A large population of elongated galaxies produces a very asymmetric distribution of projected axis ratios, as observed in high-z galaxy surveys. This indicates that the majority of the galaxies at high redshifts are not discs or spheroids but rather galaxies with elongated morphologies.
Keywords
Cite
@article{arxiv.1504.04988,
title = {Formation of elongated galaxies with low masses at high redshift},
author = {Daniel Ceverino and Joel Primack and Avishai Dekel},
journal= {arXiv preprint arXiv:1504.04988},
year = {2015}
}
Comments
7 pages, 3 figures, accepted version. Minor changes with respect to the first version