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arXiv · 1907.08035

A scenario for ultra-diffuse satellite galaxies with low velocity dispersions: the case of [KKS 2000]04

Adi Nusser
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Abstract

A scenario for achieving a low velocity dispersion for the galaxy [KKS 2000]04 (aka NGC 1052-DF2) and similar galaxies is presented. A progenitor halo corresponding to a $z=0$ halo of mass $\sim 5\times 10^{10}\; \textrm{M}_\odot$ and a low concentration parameter (but consistent with cosmological simulations) infalls onto a Milky Way-size host at early times. {Substantial removal of cold gas} from the inner regions by supernova feedback and ram pressure, assisted by tidal stripping of the dark matter in the outer regions, leads to a substantial reduction of the velocity dispersion of stars within one effective radius. In this framework, the observed stellar content of [KKS 2000]04 is associated with a progenitor mass close to that inferred from the global stellar-to-halo-mass ratio. As far as the implications of kinematics are concerned, even if at a $\sim 20 $ Mpc distance, it is argued that [KKS 2000]04 is no more peculiar than numerous early type galaxies with seemingly little total dark-matter content.

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Adi Nusser. 2020-03-09. A scenario for ultra-diffuse satellite galaxies with low velocity dispersions: the case of [KKS 2000]04. https://doi.org/10.3847/1538-4357%2Fab792c

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