Related papers: The Neutral Hydrogen Distribution in Merging Galax…
We use simulations of merging galaxies to explore the sensitivity of the morphology of tidal tails to variations of the halo mass distributions in the parent galaxies. Our goal is to constrain the mass of dark halos in well-known merging…
There are several physical processes to remove gas from galaxies in clusters, with subsequent starvation and star formation quenching: tidal interactions between galaxies, or tidal stripping from the cluster potential itself, interactions…
Mergers between red galaxies are observed to be common in the nearby Universe, and are thought to be the dominant mechanism by which massive galaxies grow their mass at late times. These ``dry'' mergers can be readily identified in very…
We present interferometric observations of HI in nine slow rotator early-type galaxies of the Atlas3D sample. With these data, we now have sensitive HI searches in 34 of the 36 slow rotators. The aggregate detection rate is 32\% $\pm$ 8\%,…
Tidal Dwarf Galaxies (TDG), concentrations of interstellar gas and stars in the tidal features of interacting galaxies, have been the subject of much scrutiny. The `smoking gun' that will prove the TDG hypothesis is the discovery of…
NGC 4013 is a nearby Sb edge-on galaxy known for its "prodigious" HI warp and its "giant" tidal stream. Previous work on this unusual object shows that it cannot be fitted satisfactorily by a canonical thin+thick disk structure. We have…
Observations of tidal disruption events (TDEs) show signs of Nitrogen enrichment reminiscent of other astrophysical sources such as active galactic nuclei (AGN) and star-forming galaxies. Given that TDEs probe the gas from a single star, it…
We apply a spectral stacking technique to Westerbork Synthesis Radio Telescope observations to measure the neutral atomic hydrogen content (HI) of nearby galaxies in and around galaxy groups at $z < 0.11$. Our sample includes 577…
We investigate the process of rapid star formation quenching in a sample of 12 massive galaxies at intermediate redshift (z~0.6) that host high-velocity ionized gas outflows (v>1000 km/s). We conclude that these fast outflows are most…
Observations of the nearby starburst galaxy NGC 253 in the 21-cm line reveal the presence of neutral hydrogen in the halo, up to 12 kpc from the galactic plane. This extra-planar HI is found only in one half of the galaxy and is…
When a star is tidally disrupted by a supermassive black hole (BH), the gas debris is stretched into an elongated stream. The longitudinal motion of the stream follows geodesics in the Kerr spacetime and the evolution in the transverse…
We have used V- and I- band images from the Hubble Space Telescope (HST) to identify compact stellar clusters within the tidal tails of twelve different interacting galaxies. The seventeen tails within our sample span a physical parameter…
Interactions between galaxies are common and are an important factor in determining their physical properties such as position along the Hubble sequence and star-formation rate. There are many possible galaxy interaction mechanisms,…
In the current galaxy formation scenarios, two physical phenomena are invoked to build disk galaxies: hierarchical mergers and more quiescent external gas accretion, coming from intergalactic filaments. Although both are thought to play a…
The hot intracluster/intragroup medium (ICM/IGM) and a high galaxy density can lead to perturbations of the galactic interstellar medium (ISM) due to ram pressure and/or tidal interaction effects. In radio polarimetry observations, both…
We present a study of the relationship between the deficiency of neutral hydrogen and the local three-dimensional number density of spiral galaxies in the Arecibo catalog of global HI measurements (Springob et al. 2005). We find that the…
It has been proposed that mergers induce starbursts and lead to important morphological changes in galaxies. Most studies so far have focused on large galaxies, but dwarfs might also experience such events, since the halo mass function is…
We present new VLA C+D-array HI observations and optical and NIR imaging of the well known interacting system NGC 4038/9, ``The Antennae''. The radio data reveal a wealth of gaseous sub-structure both within the main bodies of the galaxies…
Neutral hydrogen synthesis mapping of NGC 4532 and DDO 137, a pair of Sm galaxies on the edge of the Virgo cluster, is used to determine rotation curves for each of the galaxies and to resolve the structure and kinematics of three distinct…
In many gravitational interactions between galaxies, gas and stars that have been torn from either or both of the precursor galaxies can collect in 'tidal tails'. Star formation begins anew in these regions to produce 'tidal dwarf…