Related papers: Interactions Between Massive Dark Halos And Warped…
A simple way of explaining dark matter without modifying known Standard Model physics is to require the existence of a hidden (dark) sector, which interacts with the visible one predominantly via gravity. We consider a hidden sector…
Rates for detection of weakly-interacting massive-particle (WIMP) dark matter are usually carried out assuming the Milky Way halo is an isothermal sphere. However, it is possible that our halo is not precisely spherical; it may have some…
Spirals in galaxies have long been thought to be caused by gravitational instability in the stellar component of the disk, but discerning the precise mechanism had proved elusive. Tidal interactions, and perhaps bars, may provoke some…
The dark matter halos in $\Lambda$CDM cosmological simulations are triaxial and highly flattened. In many cases, these triaxial equilibria are also tumbling slowly, typically about their short axes, with periods of order a Hubble time.…
We consider warped equilibrium configurations for stellar and gaseous disks in the Keplerian force-field of a supermassive black hole, assuming that the self-gravity of the disk provides the only acting torques. Modeling the disk as a…
We analyse the impact of galaxy--halo misalignment on the ability of weak lensing studies to constrain the shape of dark matter haloes, using a combination of the Millennium dark matter N-body simulation and different semi-analytic galaxy…
We study the population of galactic disks expected in current hierarchical clustering models for structure formation. A rotationally supported disk with exponential surface density profile is assumed to form with a mass and angular momentum…
Warped H I gas layers in the outer regions of spiral galaxies usually display a noticeably twisted structure. This structure almost certainly arises primarily as a result of differential precession in the H I disk as it settles toward a…
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find that the orientation of the outer halo,…
We present a new mechanism to explain the frequently observed and thus certainly permanent warping of spiral galaxies. We consider the possibility of non-linear coupling between the spiral wave of the galaxy and two warp waves, such that…
In a cosmological setting, the disc of a galaxy is expected to continuously experience gravitational torques and perturbations from a variety of sources, which can cause the disc to wobble, flare and warp. Specifically, the study of…
We have extended previous analytical studies of the interaction of dark halos with galactic disks by introducing for the halo particles anisotropic distribution functions in phase space. For this purpose we have employed the shearing sheet…
We study how massive halos respond to perturbations. Through numerical solution of the coupled linearized Boltzmann-Poisson equations, we find that halos transmit and amplify disturbances over large distances within galaxies. In particular,…
This paper investigates spheroidal galaxies comprising a self-interacting dark matter halo (SIDM) plus de Vaucouleurs stellar distribution. These are coupled only via their shared gravitational field, which is computed consistently from the…
Semi-analytic models of galaxy formation typically form the spheroidal components of galaxies ("bulges"), solely through galactic major mergers. However, it is possible that non-merger events (e.g. a "fly-by" by a smaller halo) can perturb…
We construct self-consistent dynamical models for disk galaxies with triaxial, cuspy halos. We begin with an equilibrium, axisymmetric, disk-bulge-halo system and apply an artificial acceleration to the halo particles. By design, this…
Accretion discs around black holes in X-ray binary stars are warped if the spin axis of the black hole is not perpendicular to the binary orbital plane. They can also become eccentric through an instability involving a resonance with the…
Stars and their kinematics provide one of the tools available for studies of the shapes of galaxies and their halos. In this review I focus on two specific applications: the shape of the Milky Way dark halo and the shape of the LMC disk.…
The central part of a dark matter halo reacts to the presence and evolution of a bar. Not only does the halo absorb angular momentum from the disk, it can also be compressed and have its shape modified. We study these issues in a series of…
The Milky Way disc presents a warp, a flare, lopsidedness and other deviations from a purely axisymmetrical double exponential density component, both for the stellar and the gas component. Moreover, recent large-scale extended kinematics…