相关论文: Willman 1 - A Galactic Satellite at 40 kpc With Mu…

We report the discovery of seven high proper motion stars with proper motions between about 0.7 and 2.2 arcsec/yr. They were detected in an archival search using multi-epoch positions in the optical SuperCOSMOS Sky Surveys and in the…

We present a structural analysis of NGC891, an edge-on galaxy that has long been considered to be an analogue of the Milky Way. Using starcounts derived from deep HST/ACS images, we detect the presence of a thick disk component in this…

In a previous paper (Paper I) a method was developed to determine the shapes of dark matter halos of spiral galaxies from the flaring and velocity dispersion of the gas layer. Here I present the results for the almost edge-on Scd galaxy NGC…

Using Data Release 4 of the Sloan Digital Sky Survey, we have applied an optimal contrast, matched filter technique to trace the trailing tidal tail of the globular cluster Palomar 5 to a distance of 18.5 degrees from the center of the…

Stellar streams produced from dwarf galaxies provide direct evidence of the hierarchical formation of the Milky Way. Here, we present the first comprehensive study of the "LMS-1" stellar stream, that we detect by searching for wide streams…

We compare spherically-averaged radial number counts of bright (> 10^5 Lsun) dwarf satellite galaxies within 400 kpc of the Milky Way (MW) and M31 and find that the MW satellites are much more centrally concentrated. Remarkably, the two…

Twenty years ago, the mismatch between the observed number of Milky Way satellite galaxies and the predicted number of cold dark matter (CDM) subhalos was dubbed the ``missing satellites problem". Although mostly framed since in terms of…

The galaxy pair AM 1353-272 nicknamed "The Dentist's Chair" shows two ~30 kpc long tidal tails. Previous observations using multi-slit masks showed that they host up to seven tidal dwarf galaxies. The kinematics of these tidal dwarfs…

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 quantify the detectability of stellar Milky Way satellites in the Sloan Digital Sky Survey (SDSS) Data Release 5. We show that the effective search volumes for the recently discovered SDSS--satellites depend strongly on their luminosity,…

Recent observations indicate that about half of the dwarf satellite galaxies around M31 orbit in a thin plane approximately aligned with the Milky Way. It has been argued that this observation along with several other features can be…

We test the luminosity function of Milky Way satellites as a constraint for the nature of Dark Matter particles. We perform dissipationless high-resolution N-body simulations of the evolution of Galaxy-sized halo in the standard Cold Dark…

Wide-field deep gri images obtained with the Megacam of the Canada-France-Hawaii Telescope (CFHT) are used to investigate the spatial configuration of stars around five metal-poor globular cluster M15, M30, M53, NGC 5053, and NGC 5466, in a…

We present the discovery of an unusual, tidally-distorted extremely low mass white dwarf (WD) with nearly solar metallicity. Radial velocity measurements confirm that this is a compact binary with an orbital period of 2.6975 hrs and a…

We report the discovery of SDSS~J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive ($> 1\,M_\odot$ at 2$\sigma$ confidence) companion with a period of 36 hours. We use a combination of spectroscopy,…

We introduce a comprehensive analysis of multi-epoch stellar line-of-sight velocities to determine the intrinsic velocity dispersion of the ultrafaint satellites of the Milky Way. Our method includes a simultaneous Bayesian analysis of both…

In this Letter, we announce the discovery of a new satellite of the Milky Way in the constellation of Bootes at a distance of 60 kpc. It was found in a systematic search for stellar overdensities in the North Galactic Cap using Sloan…

High-accuracy absolute proper motions, radial velocities, and distances have now been measured for a number of dwarf-galaxy companions of the Milky Way, making it possible to study their 3D dynamics. Galactic orbits for 11 such galaxies…

We present a new analysis of the observed perturbations of the HI disk of the Milky Way to infer the existence of a dark sub-halo that tidally interacted with the Milky Way disk. We examine tidal interactions between perturbing dark…

As the Milky Way and its satellite system become more entrenched in near field cosmology efforts, the need for an accurate mass estimate of the Milky Way's dark matter halo is increasingly critical. With the second and early third data…