Related papers: Minor-Axis Stellar Velocity Gradients in Disk and …
The standard disc formation scenario postulates that disc forms as the gas cools and flows into the centre of the dark matter halo, conserving the specific angular momentum. Major mergers have been shown to be able to destroy or highly…
Optical and X-ray studies have established the prevalence of significant substructure in clusters of galaxies, indicating that clusters are young systems, and that recent major mergers have occurred in many clusters. Numerical simulations…
Galactic disks lie at the heart of many of the most pressing astrophysical puzzles. There are sophisticated kinetic theories that describe some aspects of galaxy disk dynamics, but extracting quantitative predictions from those theories has…
Structure of a quasi-stationary stellar cluster is modelled assuming that it is embedded in the gravitational field of a super-massive black hole. Gradual orbital decay of stellar trajectories is caused by the dissipative interaction with…
{We present, for the first time, photometric and kinematical evidence, obtained with FORS2 on the VLT, for the existence of kinematically decoupled cores (KDCs) in two dwarf elliptical galaxies; FS76 in the NGC5044 group and FS373 in the…
The kinematic properties of tidal debris from an orbiting Galactic satellite is presented, on the assumption that its central part once contained the most massive Galactic globular cluster, omega Cen. We simulate dynamical evolution of a…
We use an N-body simulation, constructed using GADGET-2, to investigate an accretion flow onto an astrophysical disk that is in the opposite sense to the disk's rotation. In order to separate dynamics intrinsic to the counter-rotating flow…
Nuclear disks and rings are frequent galaxy substructures, for a wide range of morphological types (from S0 to Sc). We have investigated the possible minor-merger origin of inner disks and rings in spiral galaxies through collisionless…
Recent observations have shown that star-forming galaxies like our own Milky Way evolve kinematically into ordered thin disks over the last ~8 billion years since z=1.2, undergoing a process of "disk settling." For the first time, we study…
We describe the kinematics of circumgalactic gas near the galactic plane, combining new measurements of galaxy rotation curves and spectroscopy of background quasars. The sightlines pass within 19--93 kpc of the target galaxy and generally…
Star formation in galaxies is triggered by a combination of processes, including gravitational instabilities, spiral wave shocks, stellar compression, and turbulence compression. Some of these persist in the far outer regions where the…
Any perturbation to a disc galaxy that creates a misalignment between the planes of the inner and outer disc, will excite a slowly evolving bending wave in the outer disc. The torque from the stiff inner disc drives a retrograde,…
We present a high resolution simulation of an idealized model to explain the origin of the two young, counter-rotating, sub-parsec scale stellar disks around the supermassive black hole SgrA* at the Center of the Milky Way. In our model,…
We present a detailed analysis of a disc galaxy forming in a high-resolution fully cosmological simulation to investigate the nature of the outer regions of discs and their relevance for the disc formation process. Specifically, we focus on…
Recent observations have suggested that circumstellar disks may commonly form around young stellar objects. Although the formation of circumstellar disks can be a natural result of the conservation of angular momentum in the parent cloud,…
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 have conducted an observing campaign with FORS at the ESO-VLT to explore the kinematical properties of spiral galaxies in distant galaxy clusters. Our main goal is to analyse transformation- and interaction processes of disk galaxies…
Misalignments between the rotation axis of stars and gas are an indication of external processes shaping galaxies throughout their evolution. Using observations of 3068 galaxies from the SAMI Galaxy Survey, we compute global kinematic…
Galaxy formation in the current cosmological paradigm is a very complex process in which inflows, outflows, interactions and mergers are common events. These processes can redistribute the angular momentum content of baryons. Recent…
Large-scale warps in the outer parts of spiral galaxy discs have been observed for almost forty years, but their origin remains obscure. We review the dynamics of warped galaxy discs. We identify several mechanisms that could excite warps,…