Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics

  title={Quantifying the Stellar Halo's Response to the LMC's Infall with Spherical Harmonics},
  author={Emily C. Cunningham and Nicol{\'a}s Garavito-Camargo and Alis J. Deason and Kathryn V. Johnston and Denis Erkal and Chervin F. P. Laporte and Gurtina Besla and Rodrigo Luger and Robyn E. Sanderson},
  journal={The Astrophysical Journal},
The vast majority of the mass in the Milky Way (MW) is in dark matter (DM); we therefore cannot directly observe the MW mass distribution and have to use tracer populations in order to infer properties of the MW DM halo. However, MW halo tracers do not only feel the gravitational influence of the MW itself. Tracers can also be affected by MW satellites; Garavito-Camargo et al. (2109) demonstrate that the Large Magellanic Cloud (LMC) induces a density wake in the MW DM, resulting in large-scale… 

All-sky dynamical response of the Galactic halo to the Large Magellanic Cloud.

The detection of both the local wake and northern overdensity in a map of the Galaxy based on 1,301 stars at Galactocentric distances between 60 and 100 kiloparsecs demonstrate that the outer halo is not in dynamical equilibrium, as is often assumed.

The nature of the Milky Way's halo revealed by the three integrals of motion

Based on a new selection method of halo stars in the Milky Way local volume, we explore the general chemo-dynamical structure of the stellar halo. The method relies on the phase-space distribution

Models of distorted and evolving dark matter haloes

We investigate the ability of basis function expansions to reproduce the evolution of a Milky Way-like dark matter halo, extracted from a cosmological zoom-in simulation. For each snapshot, the

The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites

A significant fraction of Milky Way (MW) satellites exhibit phase-space properties consistent with a coherent orbital plane. Using tailored N-body simulations of a spherical MW halo that recently

On the Stability of Tidal Streams in Action Space

In the Gaia era it is increasingly apparent that traditional static, parameterized models are insufficient to describe the mass distribution of our complex, dynamically evolving Milky Way (MW). In

Implications of the Milky Way Travel Velocity for Dynamical Mass Estimates of the Local Group

The total mass of the Local Group (LG) is a fundamental quantity that enables interpreting the orbits of its constituent galaxies and placing the LG in a cosmological context. One of the few methods

Constraining the Milky Way Halo Kinematics via Its Linear Response to the Large Magellanic Cloud

We model the response of spherical, nonrotating Milky Way (MW) dark matter and stellar halos to the Large Magellanic Cloud using the matrix method of linear response theory. Our computations

Radialization of Satellite Orbits in Galaxy Mergers

We consider the orbital evolution of satellites in galaxy mergers, focusing on the evolution of eccentricity. Using a large suite of N-body simulations, we study the phenomenon of satellite orbital

Resolving local and global kinematic signatures of satellite mergers with billion particle simulations

In this work, we present two new ∼109 particle self-consistent simulations of the merger of a Sagittarius-like dwarf galaxy with a Milky Way (MW)-like disc galaxy. One model is a violent merger

The Nature of the Milky Way’s Stellar Halo Revealed by the Three Integrals of Motion

We developed a new selection method of halo stars in the phase-space distribution defined by the three integrals of motion in an axisymmetric Galactic potential (E, L z , I 3), where I 3 is the third



Hunting for the Dark Matter Wake Induced by the Large Magellanic Cloud

Satellite galaxies are predicted to generate gravitational density wakes as they orbit within the dark matter (DM) halos of their hosts, causing their orbits to decay over time. The recent infall of


We discuss a novel approach to “weighing” the Milky Way (MW) dark matter halo, one that combines the latest samples of halo stars selected from the Sloan Digital Sky Survey (SDSS) with state of the

Measuring the slopes of mass profiles for dwarf spheroidals in triaxial cold dark matter potentials

We generate stellar distribution functions (DFs) in triaxial haloes in order to examine the reliability of slopes � �logM/�logr inferred by applying mass estimators of the form M / Re� 2 (i.e.

A Magellanic origin of the DES dwarfs

We establish the connection between the Magellanic Clouds (MCs) and the dwarf galaxy candidates discovered in the Dark Energy Survey (DES) by building a dynamical model of the MC satellite


Previous studies showed that an estimate of the likelihood distribution of the Milky Way (MW) halo mass can be derived using the properties of the satellites similar to the Large and Small Magellanic

Reflex motion in the Milky Way stellar halo resulting from the Large Magellanic Cloud infall

We present the results of N-body models of the Milky Way and Large Magellanic Cloud system and study the kinematic reflex motion in the stellar halo owing to the barycentre displacement of the

The role of dwarf galaxy interactions in shaping the Magellanic System and implications for Magellanic Irregulars

We present a novel pair of numerical models of the interaction history between the Large and Small Magellanic Clouds (LMC and SMC, respectively) and our Milky Way (MW) in light of recent


We present a new measurement of the mass of the Milky Way (MW) based on observed properties of its largest satellite galaxies, the Magellanic Clouds (MCs), and an assumed prior of a ΛCDM universe.

The influence of Sagittarius and the Large Magellanic Cloud on the stellar disc of the Milky Way Galaxy

We present N-body simulations of a Sagittarius-like dwarf spheroidal galaxy (Sgr) that follow its orbit about the Milky Way (MW) since its first crossing of the Galaxy's virial radius to the present

Simulations of sinking satellites