Related papers: Ghostly Halos in Dwarf Galaxies: Constraints on th…
In two previous papers, we presented simulations of the first galaxies in a representative volume of the Universe. The simulations are unique because we model feedback-regulated galaxy formation, using time-dependent,…
[Abridged]Ultra-faint dwarfs (UFDs) are expected to be the relics of the earliest galaxies forming in the Universe. Observations show the presence of a stellar halo around them, which can give precious insights into the evolution of UFDs.…
The relation between the galaxy stellar mass M_star and the dark matter halo mass M_h gives important information on the efficiency in forming stars and assembling stellar mass in galaxies. We present the stellar mass to halo mass ratio…
Using stellar population synthesis techniques, we explore the photometric signatures of white dwarf progenitor dominated galactic halos, in order to constrain the fraction of halo mass that may be locked-up in white dwarf stellar remnants.…
We explore the possibility that extended disks, such as that recently discovered in M31, are the result of a single dwarf (10^9--10^10 Msun) satellite merger. We carry out N-body simulations of dwarf NFW halos with embedded spheriodal…
We present results from high-resolution N-Body/SPH simulations of rotationally supported dwarf irregular galaxies moving on bound orbits in the massive dark matter halo of the Milky Way.The dwarf models span a range in disk surface density…
According to the now strongly supported concordance $\Lambda$CDM model, galaxies may be grossly described as a luminous component embedded in a dark matter halo. The density profile of these mass dominating haloes may be determined by N -…
In the first part of this contribution the observed velocity dispersions in Galactic halo dwarf spheroidal (dSph) galaxies are reviewed, and the consequences for dark matter content outlined. The results are suggestive of a dSph dark matter…
Using analytic arguments and a suite of very high resolution (10^3 Msun per particle) cosmological hydro-dynamical simulations, we argue that high redshift, z ~ 10, M ~ 10^8 Msun halos, form the smallest `baryonic building block' (BBB) for…
We use cosmological hydrodynamical simulations of the APOSTLE project along with high-quality rotation curve observations to examine the fraction of baryons in {\Lambda}CDM haloes that collect into galaxies. This 'galaxy formation…
The distribution of dark matter around galactic or cluster halos has usually been assumed to be approximately isothermal with a non-zero core radius, which is expected to be of the order of the size of the visible matter distribution.…
One of the primary goals when studying galaxy formation is to understand how the luminous component of the Universe, galaxies, relates to the growth of structure which is dominated by the gravitational collapse of dark matter haloes. The…
We predict the properties of stellar halos in galaxies of present-day virial mass $10^8 < M_{200} < 10^{12} {\rm M_\odot}$ by combining the GALFORM semi-analytic model of galaxy formation, the COCO cosmological N-body simulation, and the…
We review Galactic halo formation theories and supporting evidence, in particular kinematics and detailed chemical abundances of stars in some relevant globular clusters as well as Local Group dwarf galaxies. Outer halo red HB clusters tend…
We report the identification of elongated (triaxial or prolate) galaxies in cosmological simulations at $z\simeq2$. These are preferentially low-mass galaxies ($M_s \le 10^{9.5} \ M_\odot$), residing in dark-matter (DM) haloes with strongly…
By combining cosmological simulations with Frontier Fields project lens models we find that, in the most optimistic case, galaxies as faint as $m \approx 33 - 34$ (AB magnitude at $1.6 \rm \mu m$) can be detected in the Frontier Fields.…
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…
Gas rich sub-galactic halos with mass Mt <= 10^7.5 Msun, while incapable of forming stars due to lack of adequate coolants, contain a large fraction of baryonic mass at cosmological reionization. We show that the reionization of the…
We study a suite of extremely high-resolution cosmological FIRE simulations of dwarf galaxies ($M_{\rm halo} \lesssim 10^{10}$$M_{\odot}$), run to $z=0$ with $30 M_{\odot}$ resolution, sufficient (for the first time) to resolve the internal…
(Abridged) The hierarchical formation scenario for the stellar halo requires the accretion and disruption of dwarf galaxies, yet low-metallicity halo stars are enriched in alpha-elements compared to similar, low-metallicity stars in dwarf…