The edge of the Galaxy

  title={The edge of the Galaxy},
  author={Alis J. Deason and Azadeh Fattahi and Carlos S. Frenk and Robert J. J. Grand and Kyle A. Oman and Shea Garrison-Kimmel and Christine M. Simpson and Julio F. Navarro},
  journal={Monthly Notices of the Royal Astronomical Society},
We use cosmological simulations of isolated Milky Way (MW)-mass galaxies, as well as Local Group (LG) analogues, to define the ‘edge’ – a caustic manifested in a drop in density or radial velocity – of Galactic-sized haloes, both in dark matter and in stars. In the dark matter, we typically identify two caustics: the outermost caustic located at ∼1.4r200m, corresponding to the ‘splashback’ radius, and a second caustic located at ∼0.6r200m, which likely corresponds to the edge of the… 

Binary collisions of dark matter blobs

We describe the model-independent mechanism by which dark matter and dark matter structures heavier than ~ 8 × 1011 GeV form binary pairs in the early Universe that spin down and merge both in the

Stellar splashback: the edge of the intracluster light

We examine the outskirts of galaxy clusters in the C-EAGLE simulations to quantify the "edges" of the stellar and dark matter distribution. The radius of the steepest slope in the dark matter,

Catastrophic Dark Matter Capture

In this paper we describe a new idea which may be relevant to the formation of galaxies via the infall of baryonic matter (BM) and dark matter (DM) onto a pre-existing over density. Unlike BM, DM

The VVV survey: Long-period variable stars

Context. Long-period variable stars (LPVs) are pulsating red giants, primarily in the asymptotic giant branch phase, and they include both Miras and semi-regular variables (SRVs). Their period-age

On the Chandrasekhar Limit in Generalized Uncertainty Principles

The Chandrasekhar limit for white dwarfs has been confirmed by many astrophysical observations. However, how to obtain it theoretically in models which rely on other-than-Heisenberg’s uncertainty

Relativistic Origin of the Cutoff Parameter in Exotic Compact Objects

This article aims at presenting a relativistic origin of the cutoff parameter \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb}

On the role of cosmic mass in understanding the relationships among galactic dark matter, visible matter and flat rotation speeds

ABSTRACT With reference to our recently proposed Planck Scale White Hole Cosmology (PS-WHC) (Seshavatharam et al. 2021) or Flat Space Cosmology (PS-FSC) (Tatum et al. 2015), we make an attempt to

The Outermost Edges of the Milky Way Halo from Galaxy Kinematics

We measure for the first time the outermost edges of the Milky Way (MW) halo in terms of the depletion and turnaround radii. The inner depletion radius, r id, identified at the location of maximum

A natural boundary of dark matter haloes revealed around the minimum bias and maximum infall locations

We explore the boundary of dark matter haloes through their bias and velocity profiles. Using cosmological $N$-body simulations, we show that the bias profile exhibits a ubiquitous trough that can be




We present a systematic study of the density profiles of ΛCDM halos, focusing on the outer regions, 0.1 < r/Rvir < 9. We show that the median and mean profiles of halo samples of a given peak height

The local high-velocity tail and the Galactic escape speed

We model the fastest moving (⁠v tot >300kms −1 vtot>300kms−1 ⁠) local (D ≲ 3 kpc) halo stars using cosmological simulations and six-dimensional Gaia data. Our approach is to use our knowledge of

Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope Assets WFIRST-AFTA 2015 Report

This report describes the 2014 study by the Science Definition Team (SDT) of the Wide-Field Infrared Survey Telescope (WFIRST) mission. It is a space observatory that will address the most compelling


The boundaries of cold dark matter halos are commonly defined to enclose a density contrast Δ relative to a reference (mean or critical) density. We argue that a more physical halo boundary choice is

Splashback in accreting dark matter halos

Recent work has shown that density profiles in the outskirts of dark matter halos can become extremely steep over a narrow range of radius. This behavior is produced by splashback material on its

Gas accretion and galactic fountain flows in the Auriga cosmological simulations: angular momentum and metal redistribution

Using a set of 15 high-resolution magnetohydrodynamic cosmological simulations of Milky Way formation, we investigate the origin of the baryonic material found in stars at redshift zero. We find

The effects of dynamical substructure on Milky Way mass estimates from the high-velocity tail of the local stellar halo

We investigate the impact of dynamical streams and substructure on estimates of the local escape speed and total mass of Milky-Way-mass galaxies from modelling the high-velocity tail of local halo

ELVIS: Exploring the Local Volume in Simulations

We introduce a set of high-resolution dissipationless simulations that model the Local Group (LG) in a cosmological context: Exploring the Local Volume in Simulations (ELVIS). The suite contains 48

Statistical Properties of X-Ray Clusters: Analytic and Numerical Comparisons

We compare the results of Eulerian hydrodynamic simulations of cluster formation against virial scaling relations between four bulk quantities: the cluster mass, the dark matter velocity dispersion,

A new way of setting the phases for cosmological multiscale Gaussian initial conditions.

A convention for publishing phase information from Panphasia is defined and several of the Virgo Consortium's most recent cosmological simulations including the 303 billion particle MXXL simulation are published.