Structure, Kinematics, and Observability of the Large Magellanic Cloud’s Dynamical Friction Wake in Cold versus Fuzzy Dark Matter
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Published:2023-09-01
Issue:2
Volume:954
Page:163
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ISSN:0004-637X
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Container-title:The Astrophysical Journal
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language:
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Short-container-title:ApJ
Author:
Foote Hayden R.ORCID,
Besla GurtinaORCID,
Mocz PhilipORCID,
Garavito-Camargo NicolásORCID,
Lancaster LachlanORCID,
Sparre MartinORCID,
Cunningham Emily C.ORCID,
Vogelsberger MarkORCID,
Gómez Facundo A.ORCID,
Laporte Chervin F. P.ORCID
Abstract
Abstract
The Large Magellanic Cloud (LMC) will induce a dynamical friction (DF) wake on infall to the Milky Way (MW). The MW’s stellar halo will respond to the gravity of the LMC and the dark matter (DM) wake, forming a stellar counterpart to the DM wake. This provides a novel opportunity to constrain the properties of the DM particle. We present a suite of high-resolution, windtunnel-style simulations of the LMC's DF wake that compare the structure, kinematics, and stellar tracer response of the DM wake in cold DM (CDM), with and without self-gravity, versus fuzzy DM (FDM) with m
a
= 10−23 eV. We conclude that the self-gravity of the DM wake cannot be ignored. Its inclusion raises the wake’s density by ∼10%, and holds the wake together over larger distances (∼50 kpc) than if self-gravity is ignored. The DM wake’s mass is comparable to the LMC’s infall mass, meaning the DM wake is a significant perturber to the dynamics of MW halo tracers. An FDM wake is more granular in structure and is ∼20% dynamically colder than a CDM wake, but with comparable density. The granularity of an FDM wake increases the stars’ kinematic response at the percent level compared to CDM, providing a possible avenue of distinguishing a CDM versus FDM wake. This underscores the need for kinematic measurements of stars in the stellar halo at distances of 70–100 kpc.
Funder
National Science Foundation
DOE ∣ NNSA ∣ LDRD ∣ Lawrence Livermore National Laboratory
National Aeronautics and Space Administration
ANID ∣ Fondo Nacional de Desarrollo Científico y Tecnológico
Agencia Nacional de Investigación y Desarrollo
EC ∣ ERC ∣ HORIZON EUROPE European Research Council
Publisher
American Astronomical Society
Subject
Space and Planetary Science,Astronomy and Astrophysics