相关论文: On the origin of the asymmetric dwarf galaxy distr…

There are two fundamentally different physical origins of faint satellite galaxies: cosmological sub-structures that contain shining baryons and the fragmentation of gas-rich tidal arms thrown out from interacting galaxies during…

The arrangement of M31's dwarf galaxies exhibits anisotropy, with the majority located in the hemisphere between the Milky Way and the host galaxy. This study aims to investigate whether M31's present location is aligned with the center of…

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…

The Andromeda galaxy is surrounded by a strikingly asymmetrical distribution of satellite dwarf galaxies aligned towards the Milky Way. The standard model of cosmology predicts that most satellite galaxy systems are near-isotropic, and…

We demonstrate that the asymmetric distribution of M31 satellites cannot be produced by tides from the Milky Way as such effects are too weak. However, loosely bound associations and groups of satellites can fall into larger haloes and give…

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…

The thin, extended planes of satellite galaxies detected around both the Milky Way and Andromeda are not a natural prediction of the LCDM paradigm. Galaxies in these distinct planes may have formed and evolved in a different way (e.g.,…

The spatial distribution of dwarf galaxies around their host galaxies is a critical test for the standard model of cosmology because it probes the dynamics of dark matter halos and is independent of the internal baryonic processes of…

A significant part of the Milky Way (MW) dwarf galaxies orbit within a Vast POlar Structure (VPOS), which is perpendicular to the Galactic disc and whose origin has not yet been identified. It includes the Large Magellanic Cloud (LMC) and…

We present the discovery of three faint dwarf galaxies and a globular cluster in the halo of the Andromeda galaxy (M31), found in our MegaCam survey that spans the southern quadrant of M31, from a projected distance of ~50 kpc to \~150 kpc.…

We present the discovery of an inhomogenous, low-surface brightness, extended disk-like structure around the Andromeda galaxy (M31) based on a large kinematic survey of more than 2800 stars with the Keck/DEIMOS spectrograph. The stellar…

We propose a new model for the origin and evolution of the Local Group of Galaxies (LGG) which naturally explains the formation of the Magellanic Clouds and their large orbital angular momenta around the Galaxy. The basic idea is that an…

Large galaxies grow through the accumulation of dwarf galaxies. In principle it is possible to trace this growth history using the properties of a galaxy's stellar halo. Previous investigations of the galaxy M31 (Andromeda) have shown that…

Cosmic rays, along with stellar radiation and magnetic fields, are known to make up a significant fraction of the energy density of galaxies such as the Milky Way. When cosmic rays interact in the interstellar medium, they produce gamma-ray…

The unusual morphologies of the Andromeda spiral galaxy (M31) and its dwarf companion M32 have been characterized observationally in great detail. The two galaxies' apparent proximity suggests that Andromeda's prominent star-forming ring as…

Andromeda XVIII is an isolated dwarf galaxy 579 kpc away from the nearest large galaxy, M31. It is a candidate "backsplash galaxy" that might have been affected by a close passage to M31. We present new Keck/DEIMOS spectroscopy of Andromeda…

We present evidence to support an earlier indication that the Galaxy is embedded in an extended, highly inclined, triaxial halo outlined by the spatial distribution of companion galaxies to the Milky Way. Signatures of this spatial…

[Abridged]We compare both the Milky Way and M31 galaxies to local external disk galaxies within the same mass range, using their relative locations in the planes formed by V_flat versus M_K, j_disk, and the average Fe abundance of stars in…

We undertake an investigation into the spatial structure of the M31 satellite system utilizing the distance distributions presented in a previous publication. These distances make use of the unique combination of depth and spatial coverage…

We present the discovery of five new dwarf galaxies, Andromeda XXIII-XXVII, located in the outer halo of M31. These galaxies were found in the second year of data from the Pan-Andromeda Archaeological Survey (PAndAS) of the M31/M33…