Dark-matter-deficient galaxies in hydrodynamical simulations

Jing, Yingjie; Wang, Chunxiang; Li, Ran; Liao, Shihong; Wang, Jie; Guo, Qi; Gao, Liang

doi:10.1093/mnras/stz1839

Dark-matter-deficient galaxies in hydrodynamical simulations

Jing, Yingjie; Wang, Chunxiang; Li, Ran; Liao, Shihong; Wang, Jie; Guo, Qi; Gao, Liang

Authors

Yingjie Jing

Chunxiang Wang

Ran Li

Shihong Liao

Jie Wang

Qi Guo

Liang Gao

Abstract

Low-mass galaxies are expected to be dark-matter-dominated even within their central regions. Recently, two observations reported two dwarf galaxies in a group environment with very little dark matter in their central regions. We explore the population and origins of dark-matter-deficient galaxies (DMDGs) using two state-of-the-art hydrodynamical simulations, the EAGLE and Illustris projects. For all satellite galaxies with 109 < M* < 1010 M⊙ in groups with M200 > 1013 M⊙, we find that about 2.6percent of them in EAGLE, and 1.5percent in Illustris are DMDGs with dark matter fractions below 50percent inside two times the half-stellar-mass radius. We demonstrate that DMDGs are highly tidally disrupted galaxies, and that because dark matter has a higher binding energy than stars, mass loss of the dark matter is much more rapid than that of stars in DMDGs during tidal interactions. If DMDGs were confirmed in observations, they are expected in current galaxy formation models.

Citation

Jing, Y., Wang, C., Li, R., Liao, S., Wang, J., Guo, Q., & Gao, L. (2019). Dark-matter-deficient galaxies in hydrodynamical simulations. Monthly Notices of the Royal Astronomical Society, 488(3), 3298-3307. https://doi.org/10.1093/mnras/stz1839

Journal Article Type	Article
Acceptance Date	Jul 2, 2019
Online Publication Date	Jul 31, 2019
Publication Date	Sep 30, 2019
Deposit Date	Oct 8, 2019
Publicly Available Date	Oct 8, 2019
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	488
Issue	3
Pages	3298-3307
DOI	https://doi.org/10.1093/mnras/stz1839

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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.