相关论文: The Andromeda Stream

We report the detection of main-sequence and blue horizontal-branch stars of the Ursa Minor dwarf spheroidal galaxy beyond its tidal radius, indicating the existence of a possible tidal extension in this satellite of the Milky Way. This…

In this contribution we discuss the expected properties of our halo if our Galaxy had been built from mergers of smaller systems. Using both analytic arguments and high-resolution simulations, we find that the Galactic halo in the Solar…

This paper uses Gaussian mixture techniques to dissect the Milky Way (MW) stellar halo in angular momentum space. Application to a catalogue of 5389 stars near the plane of the Sagittarius (Sgr) stream with full 6D phase-space coordinates…

The detection of the Fermi Bubbles suggests that spiral galaxies such as the Milky Way can undergo active periods. Using gamma-ray observations, we can investigate the possibility that such structures are present in other nearby galaxies.…

Tidally-disrupted globular clusters are transformed into thin, dynamically-cold streams of stars that are extremely valuable tracers of the large- and small-scale distribution of mass in the Galaxy. Using data from the Gaia second data…

We present a review of recent studies of the formation and evolution of the Milky Way galaxy, in particular based on large samples of non-kinematically selected stars with available proper motions. The Milky Way is argued to be a reasonable…

Recent maps of the halo using RR Lyrae from Pan-STARRS1 have clearly depicted the spatial structure of the Sagittarius stream. These maps show the leading and trailing stream apocenters differ in galactocentric radius by a factor of two,…

This paper aims to retrieve the ghost streams under the pre-assumption that all the globular clusters in our Galaxy were formed in the very early merge events. The results are based on two speculations: that the specific energy and angular…

Stellar streams are sensitive laboratories for understanding the small-scale structure in our Galaxy's gravitational field. Here, we analyze the morphology of the $300S$ stellar stream, which has an eccentric, retrograde orbit and thus…

We present a panoramic map of the stellar streams of the Milky Way based upon astrometric and photometric measurements from the Gaia DR2 catalogue. In this first contribution, we concentrate on the halo at heliocentric distances beyond 5…

Near-field observations may provide tight constraints - i.e. "boundary conditions" - on any model of structure formation in the Universe. Detailed observational data have long been available for the Milky Way (e.g. Freeman $\&$…

Using spectroscopic data taken with Keck II DEIMOS by the Z-PAndAS team in the Andromeda-Triangulum region, I present a comparison of the disc and satellite systems of Andromeda with those of our own Galaxy. I discuss the observed…

Stellar streams record the accretion history of their host galaxy. We present a set of simulated streams from disrupted dwarf galaxies in 13 cosmological simulations of Milky Way (MW)-mass galaxies from the FIRE-2 suite at $z=0$, including…

The study of the Milky Way structure is vital importance for a better understanding of the universe. This study digs deeper into the structure of Milky Way Galaxys with emphasis to its spiral arms. Multiple data sources were sought…

We report the detection of a new satellite of M31, projected close to M32. And VIII is tidally distorted, with length ~10 kpc and width a few kpc. It contains 5-12 planetary nebulae (PNe) and 1-3 globular clusters, and has a velocity of…

Our Milky Way Galaxy is a typical large spiral galaxy, representative of the most common morphological type in the local Universe. We can determine the properties of individual stars in unusual detail, and use the characteristics of the…

We report on the detection of four new stellar debris streams and a new dwarf galaxy candidate in the Sloan Digital Sky Survey. Three of the streams, ranging between 3 and 15 kpc in distance and spanning between 37 and 84 degrees on the…

We report on a single star, B030D, observed as part of a large survey of objects in M31, which has the unusual radial velocity of -780 km/s. Based on details of its spectrum, we find that the star is an F supergiant, with a circumstellar…

Thanks to modern sky surveys, over twenty stellar streams and overdensity structures have been discovered in the halo of the Milky Way. In this paper, we present an analysis of spectroscopic observations of individual stars from one such…

Small stellar systems like dwarf galaxies are suggested to be the main building blocks of our Galaxy by numerical simulations in Lambda CDM models. The existence of star streams like Sagittarius tidal stream indicates that dwarf galaxies…