Related papers: Tidal Debris as a Dark Matter Probe
It has been recently claimed that the confined structure of the debris from the Sagittarius dwarf implies that the dark-matter halo of our Galaxy should be nearly spherical, in strong contrast with predictions from cold dark-matter (CDM)…
Tidal disruption of dark matter halos around proto-globular clusters in a halo of a small galaxy is studied in the context of the hierarchical clustering scenario by using semi-cosmological N-body/SPH simulations assuming the standard cold…
Observations show that stellar streams originating in satellite dwarf galaxies are frequent in the Universe. While such events are predicted by theory, it is not clear how many of the streams that are generated are washed out afterwards to…
We examine the properties of dark matter halos within a rich galaxy cluster using a high resolution simulation that captures the cosmological context of a cold dark matter universe. The mass and force resolution permit the resolution of 150…
We analyze high resolution, N-body hydrodynamical simulations of fiducial galaxy clusters to probe tidal stripping of the dark matter subhalos. These simulations include a prescription for star formation allowing us to track the fate of the…
The sensitivity of direct detection experiments depends on the phase-space distribution of dark matter near the Sun, which can be modeled theoretically using cosmological hydrodynamical simulations of Milky Way-like galaxies. However,…
Recent years have seen a series of large-scale photometric surveys with the aim of detecting substructure in nearby dwarf galaxies. Some of these objects display a varying distribution of each stellar population, reflecting their star…
A key prediction of the standard cosmological model -- which relies on the assumption that dark matter is cold, i.e. non-relativistic at the epoch of structure formation -- is the existence of a large number of dark matter substructures on…
We describe our recent attempts to model substructure in dark matter halos down to very small masses, using a semi-analytic model of halo formation. The results suggest that numerical simulations of halo formation may still be missing…
The growing trove of precision astrometric observations from the Gaia space telescope and other surveys is revealing the structure and dynamics of the Milky Way in ever more exquisite detail. We summarize the current status of our…
The Milky Way's dark matter halo is expected to host numerous low-mass subhalos with no detectable associated stellar component. Such subhalos are invisible unless their dark matter annihilates to visible states such as photons. One of the…
Dark matter comprises the bulk of the matter in the universe but its particle nature and cosmological origin remain mysterious. Knowledge of the dark matter density distribution in the Milky Way Galaxy is crucial to both our understanding…
Tidal streams in the Milky Way are sensitive probes of the population of dark-matter subhalos predicted in cold-dark-matter (CDM) simulations. We present a new calculus for computing the effect of subhalo fly-bys on cold tidal streams based…
Recent observations have revealed that high surface-brightness, metal-rich debris is present over large regions of the Andromeda (M31) stellar halo. We use a set of numerical models to determine whether extended metal-rich debris is…
A special purpose N-body simulation has been built to understand the tidal heating of the smallest dark matter substructures ($10^{-6}\msun$ and 0.01pc) from the grainy potential of the Milky Way due to individual stars in the disk and the…
In simple models of the Milky Way, tidally disrupting satellites produce long and thin---nearly one-dimensional---stellar streams. Using astrometric data from the Gaia second data release and photometry from the Dark Energy Survey, we…
Large-field multi-color images of 20 galactic globular clusters are used to investigate the presence of tidal tails around these stellar systems. Field and cluster stars are sorted with the help of color-magnitude diagrams, and star-count…
The mass distribution in the Galaxy is determined by dynamical and photometric methods. Rotation curves are the major tool for determining the dynamical mass distribution in the Milky Way and spiral galaxies. The photometric (statistical)…
We discuss recent observational and numerical work on tidal tails in globular clusters. Evidence of tidal tails has now been found in 16 Galactic globulars and 4 globulars in M31. Simulations indicate that mapping of these tidal tails over…
Observations of multiple-image gravitational lens systems suggest that the projected mass distributions of galaxy haloes may contain substantial inhomogeneities. The fraction of the halo mass in dense substructure is still highly uncertain,…