Related papers: The major merger origin of the Andromeda II kinema…
The history of the Milky Way Galaxy is written in the properties of its stellar populations. Here we analyse stars observed as part of surveys of local dwarf spheroidal galaxies, but which from their kinematics are highly probable to be…
Using a dark matter only Constrained Local UniversE Simulation (CLUES) we examine the existence of subhaloes that change their affiliation from one of the two prominent hosts in the Local Group (i.e. the Milky Way and the Andromeda galaxy)…
We present the results of several detailed numerical N-body simulations of the dynamical interactions of two equal mass disc galaxies. Both galaxies are embedded in spherical halos of dark matter and contain central bulges. Our analysis of…
We present DESI observations of the inner halo of M31, which reveal the kinematics of a recent merger - a galactic immigration event - in exquisite detail. Of the 11,416 sources studied in 3.75 hour of on-sky exposure time, 7,438 are M31…
We have explored the hypothesis that the total mass-ratio of the two main galaxies of the Local Group: Andromeda Galaxy(M31) and the Milky Way (MW) can be constrained measuring the tidal force induced by the surrounding mass distribution,…
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…
Using the Planetary Nebula Spectrograph, we have observed and measured the velocities for some 2764 PNe in the disk and halo of the Andromeda galaxy. Preliminary analysis using a basic ring model shows a rotation curve in good agreement…
The Sagittarius dwarf spheroidal (Sgr dSph) galaxy provides one of the most convincing examples of tidal interaction between satellite galaxies and the Milky Way (MW). The main body of the dwarf was recently demonstrated to have an…
In this paper we consider dynamical behavior of astrophysical objects (galaxies and dwarf galaxies) taking into account both gravitational attraction between them and cosmological expansion of the Universe. First, we obtain the general…
Observations of the pair of galaxies VV 330 with the SCORPIO multimode instrument on the 6-m Special Astrophysical Observatory telescope are presented. Large-scale velocity fields of the ionized gas in H-alfa and brightness distributions in…
We study the chemical evolution of the disks of the Milky Way (MW) and of Andromeda (M31), in order to reveal common points and differences between the two major galaxies of the Local group. We use a large set of observational data for M31,…
The Local Group (LG) consists of two giant spiral galaxies, the Milky Way (MW) and Andromeda (M31), and several smaller galaxies. The MW and M31 are approaching each other at a radial velocity of about $-109\,$km\,s$^{-1}$. Observational…
We examine the nature, possible orbits and physical properties of the progenitor of the North-western stellar stream (NWS) in the halo of the Andromeda galaxy (M31). The progenitor is assumed to be an accreting dwarf galaxy with globular…
Mergers are a common phenomenon in hierarchical structure formation, especially for massive galaxies and clusters, but their importance for dwarf galaxies in the Local Group remains poorly understood. We investigate the frequency of major…
We report the discovery of NGC 253-dw2, a dwarf spheroidal (dSph) galaxy candidate undergoing tidal disruption around a nearby spiral galaxy, NGC 253 in the Sculptor group: the first such event identified beyond the Local Group. The dwarf…
The collision of two white dwarfs is a quite frequent event in dense stellar systems, like globular clusters and galactic nuclei. In this paper we present the results of a set of simulations of the close encounters and collisions of two…
We measure the intrinsic shapes and alignments of the dwarf spheroidal (dSph) galaxies of the Local Group. We find the dSphs of the Milky Way are intrinsically flatter (mean intrinsic ellipticity $\mu_E\sim0.6$) than those of M31…
We examine the prevalence, longevity, and causes of planes of satellite dwarf galaxies, as observed in the Local Group. We use 14 Milky Way/Andromeda-(MW/M31) mass host galaxies from the FIRE-2 simulations. We select the 14 most massive…
Using the deepest and the most complete set of observations of distant galaxies, we investigate how extended disks could have formed. Observations include spatially-resolved kinematics, detailed morphologies and photometry from UV to…
Kinematical decoupling between two components of a galaxy suggests the occurrence of a second event. In disk galaxies it is usually observed as a counterrotation of the stellar disk with respect to the gaseous component and/or with respect…