Related papers: Dark Galactic subhalos and the Gaia snail
The 11 known satellite galaxies within 250 kpc of the Milky Way lie close to a great circle on the sky. We use high resolution N-body simulations of galactic dark matter halos to test if this remarkable property can be understood within the…
The kinematics of satellite galaxies moving in a dark matter halo are a direct probe of the underlying gravitational potential. Thus, the phase-space distributions of satellites represent a powerful tool to determine the galaxy-halo…
We use a series of high-resolution simulations of a `Milky-Way' halo coupled to semi-analytic methods to study the formation of our own Galaxy and of its stellar halo. The physical properties of our model Milky Way, as well as the age and…
Perturbations to stellar systems can reflect the gravitational influence of dark matter substructures. On scales much smaller than the size of a stellar system, we point out analytic connections between the stellar and dark matter…
We examine the distributions of eccentricities of orbits within mass distributions like those we see for galaxies and clusters. A comprehensive understanding of these orbital properties is essential to calculate the rates of physical…
Recent studies have shown that the passage of a massive satellite through the disk of a spiral galaxy can induce vertical wobbles in the disk and produce features such as in-plane rings and phase-space spirals. Here we analyze a…
We show that dissipationless LCDM simulations predict that the majority of the most massive subhaloes of the Milky Way are too dense to host any of its bright satellites (L_V > 10^5 L_sun). These dark subhaloes have circular velocities at…
We present a new model for the formation of stellar halos in dwarf galaxies. We demonstrate that the stars and star clusters that form naturally in the inner regions of dwarfs are expected to migrate from the gas rich, star forming centre…
We have developed a simple yet surprisingly accurate analytic scheme for tracking the dynamical evolution of substructure within larger dark halos. The scheme incorporates the effects of dynamical friction, tidal mass loss and tidal heating…
The long term time evolution of tidal dwarf satellite galaxies with two different initial densities orbiting a host galaxy that resembles the Milky Way has been studied using a large set of Newtonian N-Body simulations. From the simulations…
A pole-count analysis of the infrared 2MASS survey is presented, in order to identify faint stream-like structures within the halo of the Milky Way. Selecting stars with colours consistent with M-giant stars, we find a strong over-density…
Recent spectroscopic and high resolution $HST$-imaging observations have revealed significant numbers of ``passive'' spiral galaxies in distant clusters, with all the morphological hallmarks of a spiral galaxy (in particular, spiral arm…
We compare the dark matter halos' structural parameters derived for four Milky Way dwarf spheroidal galaxies to those of subhalos found in cosmological $N$-body simulations. We confirm that estimates of the mass at a single fixed radius are…
We present a detailed analysis of the velocity distribution and orientation of orbits of subhaloes in high resolution cosmological simulations of dark matter haloes. We find a trend for substructure to preferentially revolve in the same…
We investigate the evolution of a population of 100 dark matter satellites orbiting in the gravitational potential of a realistic model of M31. We find that after 10 Gyr, seven subhalos are completely disrupted by the tidal field of the…
The cold dark matter scenario predicts that a large number of dark subhalos should be located within the halo of each Milky-way sized galaxy. One tell-tale signature of such dark subhalos could be additional milliarcsecond-scale image…
The predicted abundance and properties of the low-mass substructures embedded inside larger dark matter haloes differ sharply among alternative dark matter models. Too small to host galaxies themselves, these subhaloes may still be detected…
Orbital properties of stars, computed from their six-dimensional phase space measurements and an assumed Galactic potential, are used to understand the structure and evolution of the Galaxy. Stellar actions, computed from orbits, have the…
We have mapped the number density and mean vertical velocity of the Milky Way's stellar disk out to roughly two kiloparsecs from the Sun using Gaia Data Release 3 (DR3) and complementary photo-astrometric distance information from…
The Sagittarius dwarf spheroidal (Sgr) is a dissolving galaxy being tidally disrupted by the Milky Way (MW). Its stellar stream still poses serious modelling challenges, which hinders our ability to use it effectively as a probe of the MW…