Related papers: Old stellar counter-rotating components in ellipti…
We study the regeneration of stellar bars triggered by a tidal interaction, using numerical simulations of either purely stellar or stellar+gas disc galaxies. We find that interactions which are sufficiently strong to regenerate the bar in…
As the formation of cosmic structure continues to proceed, we observe one of the latest stages of this process in mergers of clusters of galaxies with other clusters, groups, and galaxies. The X-ray emitting hot plasma of these systems can…
In the subset of luminous, early-type stars with strong, large-scale magnetic fields and moderate to rapid rotation, material from the star's radiatively driven stellar wind outflow becomes trapped by closed magnetic loops, forming a…
We perform general-relativistic hydrodynamical simulations of dynamical capture binary neutron star mergers, emphasizing the role played by the neutron star spin. Dynamical capture mergers may take place in globular clusters, as well as…
Stellar shells observed in many giant elliptical and lenticular as well as a few spiral and dwarf galaxies presumably result from radial minor mergers of galaxies. We show that the line-of-sight velocity distribution of the shells has a…
We use the conjugate angle of radial action ($\theta_R$), the best representation of the orbital phase, to explore the "mid-plane, north branch, south branch" and "Monoceros area" disk structures that were previously revealed in the LAMOST…
In order to try and understand its origins, we present high-quality long-slit spectral observations of the counter-rotating stellar discs in the strange S0 galaxy NGC 4550. We kinematically decompose the spectra into two counter-rotating…
The coalescence of a neutron-star binary is likely to result in the formation of a neutron-star merger remnant for a large range of binary mass configurations. The massive merger remnant shows strong oscillations, which are excited by the…
Integral field spectroscopy surveys provide spatially resolved gas and stellar kinematics of galaxies. They have unveiled a range of atypical kinematic phenomena, which require detailed modelling to understand. We present results from a…
Abr: We investigate whether the Hubble sequence can be reproduced by the relics of merger events. We verify that, at zmed=0.65, the abundant population of anomalous starbursts is mainly linked to the local spirals. Their morphologies are…
We have run high resolution N-body models simulating the encounter of a dwarf galaxy with a bright elliptical galaxy. The dwarf absorbs orbital angular momentum and shows counter-rotating features in the external regions of the galaxy. To…
We address the deviations of the scaling relations of elliptical galaxies from the expectations based on the virial theorem and homology, including the "tilt" of the "fundamental plane" and the steep decline of density with mass. We show…
We consider a new type of dynamical systems of physical interest, where two different forces act in two complementary regions of the space, namely a Keplerian attractive center sits in the inner region, while an harmonic oscillator is…
Interacting galaxies favor the formation of star clusters but are also suspected to affect their evolution through an intense and rapidly varying tidal field. Treating this complex behaviour remains out-of-reach of (semi-)analytical…
Stellar mergers and common-envelope evolution are fast (dynamical-timescale) interactions in binary stars that drastically alter their evolution. They are key to understanding a plethora of astrophysical phenomena. Stellar mergers are…
We present a study of the late-time interaction between supermassive black hole binaries and retrograde circumbinary disks during the period of gravitational wave-driven inspiral. While mergers in prograde disks have received extensive…
We use numerical simulations to investigate the orientation of the angular momentum axis of disk galaxies relative to their surrounding large scale structure. We find that this is closely related to the spatial configuration at turnaround…
We use Gauss-Hermite functions to study the line of sight velocity distributions in simulated merger remnants. Our sample contains sixteen remnants; eight produced by mergers between disk galaxies of equal mass and eight produced by mergers…
We have undertaken a large set of simulations of galaxy interactions and mergers (GalMer Project) in order to study the physical processes related to galaxy encounters. All morphological types along the Hubble sequence are considered in the…
We present near-IR K-band imaging and spectroscopy of a sample of galaxy mergers, which we use to derive light profile indices, absolute magnitudes and central velocity dispersions. It is found that the light distributions of mergers more…