The faint and ultrafaint dwarf galaxies in the Local Group form observational bedrock upon which our understanding of small-scale cosmology rests. In order to understand whether this insight generalizes, it is imperative use resolved-star techniques discover similarly satellites nearby galaxy groups. We describe search for M81 group using deep ground-based data sets from Subaru's Hyper Suprime-...

ABSTRACT We predict the dwarf galaxy detection limits for upcoming Chinese Space Station Telescope (CSST) survey that will cover 17 500 ${\rm \, deg}^{2}$ of sky with a wide field view 1.1 deg2. The point-source depth reaches 26.3 mag in g band and 25.9 i band. Constructing mock data based on designed photometric bands, we estimate recovery rate artificial galaxies from catalogues. these is str...

It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...

This article presents results of VLBI observations of regions of H2O maser activity in the Local Group galaxies M33 and IC 10. Since all position measurements were made relative to extragalactic background sources, the proper motions of the two galaxies could be measured. For M33, this provides this galaxy’s three dimensional velocity, showing that this galaxy is moving with a velocity of 190 ±...

We show that dissipative dark matter can potentially explain the large observed mass to light ratio of the dwarf satellite galaxies that have been observed in the recently identified planar structure around Andromeda, which are thought to result from tidal forces during a galaxy merger. Whereas dwarf galaxies created from ordinary disks would be dark matter poor, dark matter inside the galactic...

In the three nearest luminous galaxies, the Milky Way System, the Andromeda Galaxy and NGC 5128 the brightest globular clusters are rounder than the faintest ones. On the other hand (contrary to some previous results) the flattening of individual LMC clusters is found to be independent of their luminosities. This suggests the possibility that the relationship between the flattening and luminosi...

We present Berkeley Illinois Maryland Association (BIMA) millimeter interferometer observations of giant molecular clouds (GMCs) along a spiral arm in M31. The observations consist of a survey using the compact configuration of the interferometer and follow-up, higher-resolution observations on a subset of the detections in the survey. The data are processed using an analysis algorithm designed...

it is inferred from the symmetrical and luminous x-ray emission of fossil groups that they are mature, relaxed galaxy systems. cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (bggs), the central early-t...