相关论文: The Gas Dynamics of Shell Galaxies
The formation of disk galaxies is one of the most outstanding problems in modern astrophysics and cosmology. We review the progress made by numerical simulations carried out on large parallel supercomputers. Recent progress stems from a…
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…
In hierarchical models of galaxy formation, ellipticals form from the merging of disk galaxies drawn together by gravity as their surrounding dark halos coalesce. Using semi-analytic techniques, we are able to follow the merging, star…
Continued star formation over the lifetime of a galaxy suggests that low metalicity gas is steadily flowing in from the circumgalactic medium. Also, cosmological simulations of large-scale structure formation imply that gas is accreted onto…
The luminosity dependence of kinematical and isophotal properties of elliptical galaxies is investigated using numerical simulations of galaxy merging, combined with semi-analytical models of hierarchical structure formation. Mergers of…
We present a multiphase model for the evolution of elliptical galaxies. Diffuse gas, molecular clouds, stars and remnants are taken into account. Cloud--cloud collisions and stimulated processes are the main causes of star formation. The…
Using 3D hydrodynamic calculations we simulate formation of molecular clouds in the Galaxy. The simulations take into account molecular hydrogen chemical kinetics, cooling and heating processes. Comprehensive gravitational potential…
The rapidly improving quality and resolution of both low surface brightness observations and cosmological simulations of galaxies enables one to address the important question how the formation history is imprinted in the outer, unrelaxed…
We investigate detailed kinematical properties of simulated collisionless merger remnants of disk galaxies with mass ratios of 1:1 and 3:1. The simulations were performed by direct summation using the new special hardware device GRAPE-5. In…
[Abridged] Over the past two decades observations and theoretical simulations have established a global frame-work of galaxy formation and evolution in the young Universe. Galaxies formed as baryonic gas cooled at the centres of collapsing…
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…
The possibility that the Galactic spheroid was assembled from numerous chemically-distinct, proto-Galactic fragments is investigated using a Monte-Carlo technique designed to simulate the chemical evolution of the Galaxy in hierarchical…
We present results concerning the internal structure and kinematics of disk galaxies formed in cosmologically motivated simulations. The calculations include dark matter, gas dynamics, radiative cooling, star formation, supernova feedback…
New simulations are presented which investigate the formation of smaller groups of galaxies in a CDM like universe. The simulations follow the evolution of dark matter and gas and are performed with an SPH code adapted for the…
We analyze the star formation properties of a sample of 21 shell galaxies and 30 early-type galaxies members of interacting pairs, located in low density environments (Longhetti et al 1998a, 1998b). The study is based on new models…
In the last decades, extended old stellar clusters have been observed. These extended objects cover a large range in masses, from extended clusters or faint fuzzies to ultra compact dwarf galaxies. It has been demonstrated that these…
We investigate the evolution of star-forming gas-rich disks, using a 3D chemodynamical model including a dark halo, stars, and a two-phase interstellar medium with feedback processes from the stars. We show that galaxy evolution proceeds…
The origin of boxy and disky elliptical galaxies is investigated. The results of two collisionless N-body simulations of spiral-spiral mergers with mass ratios of 1:1 and 3:1 are discussed and the projected properties of the merger remnants…
Elliptical galaxies outside dense clusters are observed to contain small amounts (relative to spiral galaxies) of cold interstellar gas. This review discusses the atomic gas, the molecular gas, and the dust in elliptical galaxies. Field…
Evidence for wave-like corrugations are well established in the Milky Way and in nearby disc galaxies. These were originally detected as a displacement of the interstellar medium about the midplane, either in terms of vertical distance or…