相关论文: The remnant of a merger between two dwarf galaxies…
As part of the Z-PAndAS Keck II DEIMOS survey of resolved stars in our neighboring galaxy, Andromeda (M31), we have built up a unique data set of measured velocities and chemistries for thousands of stars in the Andromeda stellar halo,…
While mergers between massive galaxies and their dwarf satellites are well studied, the properties of dwarf - dwarf satellite mergers are not well constrained. Stellar streams trace satellite disruption and, in the dwarf galaxy regime, are…
In hierarchical cosmological models, galaxies grow in mass through the continual accretion of smaller ones. The tidal disruption of these systems is expected to result in loosely bound stars surrounding the galaxy, at distances that reach…
The existence of a stream of tidally stripped stars from the Sagittarius Dwarf galaxy demonstrates that the Milky Way is still in the process of accreting mass. More recently, an extensive stream of stars has been uncovered in the halo of…
Andromeda II (And II) has been known for a few decades but only recently observations have unveiled new properties of this dwarf spheroidal galaxy. The presence of two stellar populations, the bimodal star formation history (SFH) and an…
Mergers and tidal interactions between massive galaxies and their dwarf satellites are a fundamental prediction of the Lambda-Cold Dark Matter cosmology. These events are thought to provide important observational diagnostics of nonlinear…
The satellites of the Milky Way and Andromeda represent the smallest galaxies we can observe in our Universe. In this series of papers we aim to shed light on their formation and evolution using cosmological hydrodynamical simulations. In…
Although the proximity of the Andromeda galaxy (M31) offers an opportunity to understand how mergers affect galaxies, uncertainty remains about M31's most important mergers. Previous studies focused individually on the giant stellar stream…
We analyze in detail the spatial distribution and kinematic properties of two different stellar populations in Andromeda II (And II) dwarf spheroidal galaxy. We obtained their detailed surface density maps, together with their radial…
In the most prominent current scenario of galaxy formation, galaxies form hierarchically through the merger of smaller systems. Such mergers could leave behind dynamical signatures which may linger long after the event. In particular, the…
Recent observations have shown that the majority of the Andromeda galaxy's satellites are aligned in a thin plane. On the theoretical side it has been proposed that galaxies acquire their gas via cold streams. In addition, numerical…
Prolate rotation (i.e. rotation around the long axis) has been reported for two Local Group dwarf galaxies: Andromeda II, a dwarf spheroidal satellite of M31, and Phoenix, a transition type dwarf galaxy. The prolate rotation may be an…
Standard cosmology predicts that dwarfs were the first galaxies to be formed in the Universe and that many of them merge afterwards to form bigger galaxies such as the Milky Way. This process would have left behind traces such as tidal…
A candidate diffuse stellar substructure was previously reported in the halo of the nearby dwarf starburst galaxy NGC 4449 by Karachentsev et al. We map and analyze this feature using a unique combination of deep integrated-light images…
Dwarf satellite galaxies are thought to be the remnants of the population of primordial structures that coalesced to form giant galaxies like the Milky Way. An early analysis noted that dwarf galaxies may not be isotropically distributed…
Recent observations of our neighbouring galaxy M31 have revealed that its disk was shaped by widespread events. The evidence for this includes the high dispersion ($V/\sigma$ $\le$ 3) of stars older than 2 Gyr, and a global star formation…
Tidal streams and stellar shells are naturally formed in galaxy interactions and mergers. The Giant Stellar Stream (GSS), the North-East (NE), and Western (W) stellar shelves observed in Andromeda galaxy (M31) are examples of these…
Understanding galaxy formation involves look-back and fossil-record studies of distant and nearby galaxies, respectively. Debris trails in our Galaxy's spheroidal halo of old stars provide evidence of "bottom-up" formation via tidal…
The relics of disrupted satellite galaxies around the Milky Way and Andromeda have been found, but direct evidence of a satellite galaxy in the early stages of being disrupted has remained elusive. We have discovered a dwarf satellite…
To unveil a progenitor of the Andromeda Giant Stellar Stream, we investigate the interaction between an accreting satellite galaxy and the Andromeda Galaxy using an $N$-body simulation. A comprehensive parameter study with 247 models is…