Related papers: White Dwarfs and Dark Matter
The simplest interpretation of the microlensing events towards the Large Magellanic Cloud detected by the MACHO and EROS collaborations is that about one third of the halo of our own Milky Way galaxy exists in the form of objects of around…
The galactic halo likely grew over time in part by assembling smaller galaxies, the so-called building blocks. We investigate if the properties of these building blocks are reflected in the halo white dwarf (WD) population in the Solar…
The Milky Way's stellar halo, which extends to $>100$ kpc, encodes the evolutionary history of our Galaxy. However, most studies of the halo to date have been limited to within a few kpc of the Sun. Here, we characterize differences between…
Elucidating dark matter density profiles in the Galactic dwarf satellites is essential to understanding not only the quintessence of dark matter, but also the evolution of the satellites themselves. In this work, we present the current…
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)…
Galactic double white dwarfs were postulated as a source of confusion limited noise for LISA, the future space-based gravitational wave observatory. Until very recently, the Galactic population consisted of a relatively well studied disk…
Over the past five years, searches in Sloan Digital Sky Survey data have more than doubled the number of known dwarf satellite galaxies of the Milky Way, and have revealed a population of ultra-faint galaxies with luminosities smaller than…
White dwarf stars constitute the final evolutionary stage for more than 95 per cent of all stars. The Galactic population of white dwarfs conveys a wealth of information about several fundamental issues and are of vital importance to study…
Near-field observations may provide tight constraints - i.e. "boundary conditions" - on any model of structure formation in the Universe. Detailed observational data have long been available for the Milky Way (e.g. Freeman $\&$…
The present day chemical and dynamical properties of the Milky Way bear the imprint of the Galaxy's formation and evolutionary history. One of the most enduring and critical debates surrounding Galactic evolution is that regarding the…
Ultracool subdwarfs are low luminosity, late-type M and L dwarfs that exhibit spectroscopic indications of subsolar metallicity and halo kinematics. Their recent discovery and ongoing investigation have led to new insights into the role of…
The hierarchical theory of galaxy formation rests on the idea that smaller galactic structures merge to form the galaxies that we see today. The past decade has provided remarkable observational support for this scenario, driven in part by…
The evolution of the observational results of microlensing towards the LMC and some of the suggested interpretations to account for them are discussed. It is emphasized that the results at present are indicative of a lensing population of…
We compare the structure and kinematics of the 11 known satellites of the Milky Way with high resolution simulations of the formation of its dark halo in a LambdaCDM universe. In contrast to earlier work, we find excellent agreement. The…
The recent discovery of microlensing of stars in the Large Magellanic Cloud has excited much interest in the nature of the lensing population. Detailed analyses indicate that the mass of these objects ranges from 0.3-0.8 solar masses,…
We present a schematic model for the formation of baryonic galactic halos and hot gas in the Local Group and the intergalactic medium. We follow the dynamics, chemical evolution, heat flow and gas flows of a hierarchy of scales, including:…
The nature of the dark matter in the haloes of galaxies is one of the outstanding questions in astrophysics. All stellar candidates, until recently thought to be likely baryonic contributions to the Halo of our Galaxy, are shown to be ruled…
Numerical simulations of dwarf spheroidal galaxies undergoing several close encounters with the Milky Way are described. By comparing our models to observed properties of the recently discovered dwarf galaxy in Sagittarius (Sgr), we discuss…
The hierarchical clustering inherent in Lambda-CDM cosmology seems to produce many of the observed characteristics of large-scale structure. But some glaring problems still remain, including the over-prediction (by a factor 10) of the…
We present kinematics of a sample of 107 DA white dwarfs from the SPY project and discuss kinematic criteria for a distinction of thin disk, thick disk, and halo populations. This is the first homogeneous sample of white dwarfs for which 3D…