Related papers: Extended gas in interacting systems
The evolution of Ly-alpha absorber counts is simulated for a model population of absorbing galaxies. The distribution of gas relative to galaxies could evolve between moderate and low redshifts, but constraints are needed on the strength…
Quasars, powered by gas accretion onto supermassive black holes, rank among the most energetic objects of the Universe. While they are thought to be ignited by galaxy mergers and affect the surrounding gas, observational constraints on both…
X-ray observations of hot gas in galaxy groups indicate higher entropies than can be achieved in the accretion shocks as it fell into the dark halos. It has been proposed that this entropy excess results from some universal external heating…
We investigate the kinematics of the molecular gas in a sample of seven edge-on (i>60{\deg}) galaxies identified as hosting large-scale outflows of ionised gas, using ALMA CO(1-0) observations at ~ 1kpc resolution. We build on Hogarth et…
We consider the most commonly occurring circumstances which apply to galaxies, namely membership in galaxy groups of about $10^{13}h^{-1} M_\odot$ total mass, and estimate the accompanying physical conditions of intergalactic medium (IGM)…
Substantial numbers of morphologically regular early-type (elliptical and lenticular) galaxies contain molecular gas, and the quantities of gas are probably sufficient to explain recent estimates of the current level of star formation…
Simulations predict that galaxies grow primarily through the accretion of gas that has not gone through an accretion shock near the virial radius and that this cold gas flows towards the central galaxy along dense filaments and streams.…
We present a new scenario in which massive intragroup HI clouds are the high-density parts of large HI rings/arcs formed by dynamical interaction between galaxy groups and gas-rich, low surface brightness (LSB) galaxies with extended gas…
We present the results of our analysis of the frequencies of galaxies with tidal tails and M51-type galaxies in several deep fields of the Hubble Space Telescope (HDF-N, HDF-S, HUDF, GOODS, GEMS). In total, we have found about seven hundred…
We present the results of HI observations of five dust-lane ellipticals with the Australia Telescope Compact Array. Two galaxies (NGC 3108 and NGC 1947) are detected, and sensitive upper limits are obtained for the other three. In the two…
The distribution and kinematics of the molecular gas in elliptical galaxies give information on the origin and history of the gas and the rate of star formation activity in ellipticals. I describe some preliminary results of a survey which…
We compare the cosmic evolution of star formation rates in galaxies with that of their neutral hydrogen densities. We highlight the need for neutral hydrogen to be continually replenished from a reservoir of ionized gas to maintain the…
High--resolution 2D--MHD numerical simulations have been carried out to investigate the effects of continuing infall of clumpy gas in extended HI galactic disks. Given a certain accretion rate, the response of the disk depends on its…
The chemical composition of gas in galaxies can be measured in detail from absorption spectroscopy. By studying gas in galaxies in this way, it is possible to investigate the small and faint galaxies, which are the most numerous in the…
Recent observations have found extended multi-phase gas in a significant fraction of massive elliptical galaxies. We perform high-resolution three-dimensional hydrodynamical simulations of two idealized elliptical galaxies -- one…
The dark matter content of galaxies is usually determined from galaxies in dynamical equilibrium, mainly from rotationally supported galactic components. Such determinations restrict measurements to special regions in galaxies, e.g. the…
Galaxies in the local universe are most commonly found in groups and are thought to be "pre-processed" in this environment before being consumed by clusters. Yet we know very little about the gastrophysics of these systems, how they evolve…
We present the two-point cross-correlation function between Lyman $\alpha$ absorbers and HI galaxies in the nearby Universe ($0.01 \le z \le 0.057$). We use absorbers from 21 QSO sightlines from the Survey of the Low-Redshift Intergalactic…
Galaxy-galaxy interactions and large scale galaxy bars are usually considered as the two main mechanisms for driving gas to the centres of galaxies. By using large samples of galaxy pairs and visually classified bars from the Sloan Digital…
Understanding the hydrodynamical processes and conditions at the interface between the Magellanic Stream (MS) and the Galactic halo is critical to understanding the MS and by extension, gaseous tails in other interacting galaxies. These…