Isolated dark matter deprived galaxies in hydrodynamical simulations: real objects or artefacts? [GA]

http://arxiv.org/abs/1907.03542


We searched for isolated dark matter deprived galaxies within several state-of-the-art hydrodynamical simulations: Illustris, IllustrisTNG, EAGLE, and Horizon-AGN and found a handful of promising objects in all except Horizon-AGN. While our initial goal was to study their properties and evolution, we quickly noticed that all of them were located at the edge of their respective simulation boxes. After carefully investigating these objects using the full particle data, we concluded that they are not merely caused by a problem with the algorithm identifying bound structures. We provide strong evidence that these oddballs were created from regular galaxies that get torn apart due to unphysical processes when crossing the edge of the simulation box. We show that these objects are smoking guns likely indicating issue with the implementation of the periodic boundary conditions of the particle data in Illustris, IllustrisTNG, and EAGLE.

Read this paper on arXiv…

C. Saulder, O. Snaith, C. Park, et. al.
Tue, 9 Jul 19
45/81

Comments: submitted to MNRAS, 24 pages (8 pages main text with 2 figures, but also a very long appendix with 40 supplementary figures)