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Galaxies lacking dark matter produced by close encounters in a cosmological simulation

Authors :
Jorge Moreno
Shany Danieli
James S. Bullock
Robert Feldmann
Philip F. Hopkins
Onur Çatmabacak
Alexander Gurvich
Alexandres Lazar
Courtney Klein
Cameron B. Hummels
Zachary Hafen
Francisco J. Mercado
Sijie Yu
Fangzhou Jiang
Coral Wheeler
Andrew Wetzel
Daniel Anglés-Alcázar
Michael Boylan-Kolchin
Eliot Quataert
Claude-André Faucher-Giguère
Dušan Kereš
University of Zurich
Moreno, Jorge
Publication Year :
2022
Publisher :
Nature Publishing Group, 2022.

Abstract

The standard cold dark matter plus cosmological constant model predicts that galaxies form within dark-matter haloes, and that low-mass galaxies are more dark-matter dominated than massive ones. The unexpected discovery of two low-mass galaxies lacking dark matter immediately provoked concerns about the standard cosmology and ignited explorations of alternatives, including self-interacting dark matter and modified gravity. Apprehension grew after several cosmological simulations using the conventional model failed to form adequate numerical analogues with comparable internal characteristics (stellar masses, sizes, velocity dispersions and morphologies). Here we show that the standard paradigm naturally produces galaxies lacking dark matter with internal characteristics in agreement with observations. Using a state-of-the-art cosmological simulation and a meticulous galaxy-identification technique, we find that extreme close encounters with massive neighbours can be responsible for this. We predict that approximately 30 percent of massive central galaxies (with at least 1e11 solar masses in stars) harbour at least one dark-matter-deficient satellite (with 1e8 - 1e9 solar masses in stars). This distinctive class of galaxies provides an additional layer in our understanding of the role of interactions in shaping galactic properties. Future observations surveying galaxies in the aforementioned regime will provide a crucial test of this scenario.<br />55 pages, 4 figures, 13 supplementary figures. 29 pages, 4 figures. Accepted for publication in Nature Astronomy. To appear on 14-February-2022. Published version: https://www.nature.com/articles/s41550-021-01598-4

Details

Language :
English
Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....bc8607e7f3a510d2f12f1dcc6a3d0f15