Liao, Shihong and Gao, Liang and Frenk, Carlos S. and Grand, Robert J. J. and Guo, Qi and Gómez, Facundo A. and Marinacci, Federico and Pakmor, Rüdiger and Shao, Shi and Springel, Volker (2019) 'Ultra-diffuse galaxies in the Auriga simulations.', Monthly notices of the Royal Astronomical Society., 490 (4). 5182-5195.
We investigate the formation of ultra-diffuse galaxies (UDGs) using the Auriga high-resolution cosmological magneto-hydrodynamical simulations of Milky Way-sized galaxies. We identify a sample of 92 UDGs in the simulations that match a wide range of observables such as sizes, central surface brightness, Sérsic indices, colors, spatial distribution and abundance. Auriga UDGs have dynamical masses similar to normal dwarfs. In the field, the key to their origin is a strong correlation present in low-mass dark matter haloes between galaxy size and halo spin parameter. Field UDGs form in dark matter haloes with larger spins compared to normal dwarfs in the field, in agreement with previous semi-analytical models. Satellite UDGs, on the other hand, have two different origins: ∼55% of them formed as field UDGs before they were accreted; the remaining ∼45% were normal field dwarfs that subsequently turned into UDGs as a result of tidal interactions.
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||https://doi.org/10.1093/mnras/stz2969|
|Publisher statement:||This article has been accepted for publication in the Monthly notices of the Royal Astronomical Society ©: 2019 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.|
|Date accepted:||18 October 2019|
|Date deposited:||29 October 2019|
|Date of first online publication:||23 October 2019|
|Date first made open access:||29 October 2019|
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