Related papers: Does M31 result from an ancient major merger?
We present a color-magnitude diagram (CMD) for a field in the giant tidal stream of the Andromeda galaxy (M31). These observations, taken with the Advanced Camera for Surveys on the Hubble Space Telescope, are 50% complete at V~30 mag,…
Inspired by recent studies of the Milky Way--LMC interaction and its implications for the Milky Way's global dynamical history, we investigate how the massive satellite galaxy M33 influences Andromeda's (M31) center of mass (COM) position…
The fraction of distant disks and mergers is still debated, while 3D-spectroscopy is revolutionizing the field. However its limited spatial resolution imposes a complimentary HST imagery and a robust analysis procedure. When applied to…
The G31.41+0.31 (G31) hot molecular core (HMC) is a high-mass protocluster showing accelerated infall and rotational spin-up that is well studied at high-angular resolution. To complement the accurate view of the small scale in G31, we have…
The Milky Way (MW) offers a uniquely detailed view of galactic structure and is often regarded as a prototypical spiral galaxy. But recent observations indicate that the MW is atypical: it has an undersized supermassive black hole at its…
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…
The advent of Gaia's 2nd data release in combination with large spectroscopic surveys are revolutionizing our understanding of the Galaxy. Thanks to these and the knowledge accumulated thus far, a more mature picture of the evolution of the…
From $>1000$ orbits of HST imaging, we present deep homogeneous resolved star color-magnitude diagrams that reach the oldest main sequence turnoff and uniformly measured star formation histories (SFHs) of 36 dwarf galaxies ($-6 \ge M_V \ge…
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,…
We investigate the origin of the scatter in the supermassive black hole (BH) masses for galaxies in the L* regime, using the ARTEMIS and EAGLE simulations. By classifying galaxies based on their central BH / galaxy stellar masses ratios, we…
We use numerical simulations to examine the structure of merger remnants resulting from collisions of gas-rich spiral galaxies. When the gas fraction of the progenitors is small, the remnants structurally and kinematically resemble…
Context. Giant Low Surface Brightness galaxies, such as Malin 1, host extended stellar and gaseous disks exceeding 100 kpc in radius. Their formation and evolution remain debated, with interactions with satellite galaxies and accretion…
The Milky Way (MW) and M31 both harbor massive satellite galaxies, the Large Magellanic Cloud (LMC) and M33, which may comprise up to 10 per cent of their host's total mass. Massive satellites can change the orbital barycentre of the…
Numerical simulations have shown that massive dark matter haloes, which today host galaxy clusters, assemble their mass over time alternating periods of quiescent accretion and phases of rapid growth associated with major merger episodes.…
We use the Bullock & Johnston suite of simulations to study the density profiles of L*-type galaxy stellar haloes. Observations of the Milky Way and M31 stellar haloes show contrasting results: the Milky Way has a `broken' profile, where…
The concentration parameter is a key characteristic of a dark matter halo that conveniently connects the halo's present-day structure with its assembly history. Using 'Dark Sky', a suite of cosmological $N$-body simulations, we investigate…
In the CDM cosmological framework structures grow from merging with smaller structures. Merging should have observable effects on galaxies including destroying disks and creating spheroids. This proceeding aims to give a brief overview of…
The Milky Way's (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the "last major merger." Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where…
We use N-body cosmological simulations and empirical galaxy models to study the merger history of dwarf-mass galaxies (with M_halo~10^10 M_Sun). Our input galaxy models describe the stellar mass-halo mass relation, and the galaxy occupation…
Galaxies with Milky Way-like stellar masses have a wide range of bulge and black hole masses; in turn, these correlate with other properties such as star formation history. While many processes may drive bulge formation, major and minor…