Related papers: Exponential Galaxy Disks from Stellar Scattering
Conditions for the fragmentation of expanding shells due to gravitational instability are discussed. The self-similar analytical solution is compared with the results of 3-dimensional computer simulations for the expansion into homogeneous…
Several stars show deep transits consistent with discs of roughly 1 Solar radius seen at moderate inclinations, likely surrounding planets on eccentric orbits. We show that this configuration arises naturally as a result of planet-planet…
The truncation of stellar discs is not abrupt but characterized by a continuous distancing from the exponential profile. There exists a truncation curve, $t(r)$, ending at a truncation radius, $r_t$. We present here a theoretical model in…
We investigate the evolution of mass density profiles in secular disk galaxy models, paying special attention to the development of a two-component profile from a single initial exponential disk free of cosmological evolution (i.e., no…
A model of a galactic disk is presented which extends the homogeneous one zone models by incorporating propagation of material and energy in the disk. For reasonable values of the parameters the homogeneous steady state is unstable to the…
We present here a self-consistent, tridimensional model of a disc galaxy composed by a number of ellipsoidal distributions of matter having different flattening and density profile. The model is self-consistent and takes into account the…
We analyse a high-resolution, fully cosmological, hydrodynamical disc galaxy simulation, to study the source of the double-exponential light profiles seen in many stellar discs, and the effects of stellar radial migration upon the…
We study gravitational lensing by spiral galaxies, using realistic models consisting of halo, disk, and bulge components combined to produce a flat rotation curve. Proper dynamical normalization of the models is critical because a disk…
We investigate the evolution of galactic disks in N-body Tree-SPH simulations. We find that disks, initially truncated at three scale-lengths, can triple their radial extent, solely driven by secular evolution. Both Type I (single…
Models of disc galaxies which invoke viscosity-driven radial flows have long been known to provide a natural explanation for the origin of stellar exponential discs, under the assumption that the star formation and viscous timescales are…
The circular velocities of the inner region of disk galaxies are predicted by standard physics but velocities beyond the stellar disks are not consistent with Newtonian physics if the material there is in stable circular orbits. However,…
I review observations of truncations of stellar disks and models for their origin, compare observations of truncations in moderately inclined galaxies to those in edge-on systems and discuss the relation between truncations and HI-warps and…
We have carried out a sample survey in UBVR photometry and proper motions in different directions in the Galaxy, as part of an investigation of galactic structure and evolution. Three fields in the direction of galactic anticentre, centre…
Stellar migration, whether due to trapping by transient spirals (churning), or to scattering by non-axisymmetric perturbations, has been proposed to explain the presence of stars in outer disks. After a review of the basic theory, we…
We consider the possibility that an infalling bulge core or stellar cluster could form an eccentric disk, following tidal disruption by a massive black hole in the center of a galaxy. As a function of central black hole mass, we constrain…
Galaxy formation models typically assume that the size and rotation speed of galaxy disks are largely dictated by the mass, concentration, and spin of their surrounding dark matter haloes. Equally important, however, are the fraction of…
We present the results from our deep optical imaging survey \mu_lim=26-27 V-mag/arcsec^2 of a morphologically selected sample of 72 edge-on disk galaxies. The question of the global structure of galactic stellar disks, especially the radial…
We present first results concerning the metallicities and stellar populations of galaxies formed in a cosmologically motivated simulation. The calculations include dark matter, gas dynamics, radiation processes, star formation, supernovae…
We consider the effects of eccentricity on the fragmentation of gravitationally unstable accretion disks, using numerical hydrodynamics. We find that eccentricity does not affect the overall stability of the disk against fragmentation, but…
High surface density, rapidly star-forming galaxies are observed to have $\approx 50-100\,{\rm km\,s^{-1}}$ line-of-sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale…