Related papers: Implications of White Dwarf Galactic Halos
We establish constraints on the mass and abundance of black holes in the Galactic halo by determining their impact on globular clusters which are conventionally considered to be little evolved. Using detailed Monte Carlo simulations and…
Dwarf spheroidal galaxies that form in halo substructures provide stringent constraints on dark matter annihilation. Many ultrafaint dwarfs discovered with modern surveys contribute significantly to these constraints. At present, because of…
It is now established that several of the Local Group dwarf Spheroidal galaxies (dSphs) have large mass-to-light ratios. We consider the possibility that the dark matter in the halos of dSphs is composed of massive black holes with masses…
We present a stellar populations analysis of the first release of the CFHTLS (Canada-France-Hawai Telescope Legacy Survey) data. A detailed comparison between the Besan\c{c}on model of the Galaxy and the first data release of the…
The shape of the luminosity function of white dwarfs (WDLF) is sensitive to the characteristic cooling time and, therefore, it can be used to test the existence of additional sources or sinks of energy such as those predicted by alternative…
The unexpected high incidence of carbon-enhanced, s-process enriched unevolved stars amongst extremely metal-poor stars in the halo provides a significant constraint on the Initial Mass Function (IMF) in the early Galaxy. We argue that…
Although the stellar initial mass function (IMF) has only been directly determined in star clusters it has been manifoldly applied on galaxy-wide scales. But taking the clustered nature of star formation into account the galaxy-wide IMF is…
The difference in density profiles of the contributions from different density peaks to dark matter halos results in certain expectations about the Milky Way's stellar halo. We cut our simulated halo stars into two populations: those…
The presence (and nature) of variations in the stellar initial mass function (IMF) at substantially sub-solar masses and metallicities ($m$$<$0.5M$_{\odot}$, [M/H]$\lesssim$$-$1) remains poorly constrained. Predictions from simulations vary…
The conditions that affect the formation of stars in radiatively and mechanically active environments are quite different than the conditions that apply to our local interstellar neighborhood. In such galactic environments, a variety of…
Recent results of microlensing surveys, show that 10-20% of the dark halo mass of the Milky Way consists of compact objects. The masses of these compact objects range from 0.1 to 1 solar mass. New theoretical cooling models for white…
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…
Using deep HST/ACS observations, we demonstrate that the sub-solar stellar initial mass function (IMF) of 6 ultra-faint dwarf Milky Way Satellites (UFDs) is more bottom light than the IMF of the Milky Way disk. Our data have a lower mass…
In this study, we modify the semi-analytic model Galacticus in order to accurately reproduce the observed properties of dwarf galaxies in the Milky Way. We find that reproducing observational determinations of the halo occupation fraction…
In astrophysics, we often aim to estimate one or more parameters for each member object in a population and study the distribution of the fitted parameters across the population. In this paper, we develop novel methods that allow us to take…
Observations have not yielded convincing results concerning the form of the stellar initial mass function (IMF) or its variations in space and time, so it is proposed that theoretical models may provide useful guidance. Several classes of…
The total extragalactic background radiation can be an important test of the global star formation history (SFH). Using direct observational estimates of the SFH, along with standard assumptions about the initial mass function (IMF), we…
Globular star clusters are among the first stellar populations to have formed in the Milky Way, and thus only a small sliver of their initial spectrum of stellar types are still burning hydrogen on the main-sequence today. Almost all of the…
Thanks to the recent space-borne mission Gaia, there is a nearly complete sample of white dwarfs up to about 100 parsecs from the Sun, which may have very diverse origins. We aim to compute the Galactic orbits for white dwarfs observed in…
The initial-final mass relation represents a mapping between the mass of a white dwarf remnant and the mass that the hydrogen burning main-sequence star that created it once had. The relation thus far has been constrained using a sample of…