Related papers: Extended stellar substructure surrounding the Bo\"…
I present results of the analysis of a set of images obtained in the field of the Milky Way globular cluster NGC 6362 using the Dark Energy Camera, which is mounted in the 4.0m Victor Blanco telescope of the Cerro-Tololo Interamerican…
As part of our survey for substructure in the Milky Way halo as traced by giant stars, and to look for tidal stellar debris in the halo viable for measurement of the Galactic mass potential with SIM, we explore the distribution of stars…
White dwarf stars that enter the tidal radius of black holes with masses $\lesssim$ $10^5$ M$_{\odot}$ are doomed to be ripped apart by tidal forces. Black holes in this mass range between stellar black holes and supermassive black holes…
Using a high resolution N-body simulation of a two-component dwarf galaxy orbiting in the potential of the Milky Way, we study two effects that lead to significant biases in mass estimates of dwarf spheroidal galaxies. Both are due to the…
We investigate a wide range of possible evolutionary histories for the recently discovered Bootes dwarf spheroidal galaxy, a Milky Way satellite. By means of N-body simulations we follow the evolution of possible progenitor galaxies of…
[Abridged] Within the hierarchical framework for galaxy formation, minor merging and tidal interactions are expected to shape all large galaxies to the present day. As a consequence, most seemingly normal disk galaxies should be surrounded…
Tidal debris streams from galaxy satellites can provide insight into the dark matter distribution in halos. This is because we have more information about stars in a debris structure than about a purely random population of stars: we know…
We present the results of a low-resolution spectral abundance study of 25 stars in the Bootes I dwarf spheroidal (dSph) galaxy. The data were obtained with the LRIS instrument at Keck Observatory, and allow us to measure [Fe/H], [C/Fe], and…
Dwarf galaxies are valuable laboratories for dynamical studies related to dark matter and galaxy evolution, yet it is currently unknown just how physically extended their stellar components are. Satellites orbiting the Galaxy's potential…
We present an investigation of small-scale-structure in the distribution of large molecules/dust in the interstellar medium through observations of diffuse interstellar bands (DIBs). High signal-to-noise optical spectra were recorded…
We have examined the stellar structure of 10 nearby, low stellar mass (10^6 to 6 x 10^7 Msolar) dwarf irregular galaxies by fitting ellipses as a function of surface brightness on ultra-deep V images. These are compared to far ultraviolet…
We have obtained spectra of three QSO/AGNs with the GHRS aboard the Hubble Space Telescope to search for absorption from low column density gas in the halo of the dwarf spheroidal (dSph) galaxy Leo I. The probe sightlines pass 2.1, 3.7, and…
We use deep imaging from the Dark Energy Camera to explore the peripheral regions of nine globular clusters in the outer halo of the Milky Way. Apart from Whiting 1 and NGC 7492, which are projected against the Sagittarius stream, we see no…
In this paper we derive the gravitational wave stochastic background from tidal disruption events (TDEs). We focus on both the signal emitted by main sequence stars disrupted by super-massive black holes (SMBHs) in galaxy nuclei, and on…
Using the Wide Field Imager (WFI) at the ESO 2.2m telescope at La Silla and the CPAPIR camera at the CTIO 1.5m telescope at Cerro Tololo, we have performed an extensive, multiband photometric survey of the open cluster IC2391 (D~146pc,…
We present an AAOmega spectroscopic study of red giant stars in Bootes I, which is an ultra-faint dwarf galaxy, and Segue 1, suggested to be either an extremely low-luminosity dwarf galaxy or a star cluster. Our focus is quantifying the…
We present high-resolution ($\lesssim 0.1''$) Hubble Space Telescope (HST)/Wide Field Camera 3 (WFC3) imaging of the near edge-on ($i{\sim}80^\circ$) protoplanetary disk IRAS 23077+6707 ("Dracula's Chivito") obtained across six broadband…
Two studies have recently reported the discovery of pronounced Halo substructure in the Sloan Digital Sky Survey (SDSS) commissioning data. Here we show that this Halo substructure is almost in its entirety due to the expected tidal stream…
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…
We report here the discovery of an apparent excess of 2MASS M giant candidates with dereddened 0.85 < J-K_S < 1.2 spanning a considerably large area of the celestial sphere between, at least, $100\degr < l < 150\degr$ and $-20\degr > b >…