相关论文: Stellar Bar Evolution in Cuspy and Flat-Cored Tria…
Young stellar bars in disk galaxies experience a vertical buckling instability which terminates their growth and thickens them, resulting in a characteristic peanut/boxy shape when viewed edge on. Using N-body simulations of galactic disks…
Cosmological N-body simulations indicate that the dark matter haloes of galaxies should be generally triaxial. Yet, the presence of a baryonic disc is believed to alter the shape of the haloes. Here we aim to study how bar formation is…
We report idealized simulations that mimic the growth of galaxy disks embedded in responsive halos and bulges. The disks manifested an almost overwhelming tendency to form strong bars that we found very difficult to prevent. We found that…
The halo plays a crucial role in the evolution of barred galaxies. Its near-resonant material absorbs angular momentum emitted from some of the disc particles and helps the bar become stronger. As a result, a bar (oval) forms in the inner…
We study formation and evolution of bar-disk systems in fully self-consistent cosmological simulations of galaxy formation in the LCDM WMAP3 Universe. In a representative model we find that the first generation of bars form in response to…
We study the mechanisms and evolutionary phases of bar formation in n-body simulations of a stellar disc and dark matter halo system using harmonic basis function expansion analysis to characterize the dynamical mechanisms in bar evolution.…
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…
Many barred galaxies, possibly including the Milky Way, have cusps in the centres. There is a widespread belief, however, that usual bar instability taking place in bulgeless galaxy models is impossible for the cuspy models, because of the…
We investigate the connection between the vertical structure of stellar discs and the formation of bars using high-resolution simulations of galaxies in isolation and in the cosmological context. In particular, we simulate a suite of…
In this review, I discuss just three aspects of the stability and evolution of galactic discs. (1) I first review our understanding of the bar instability and how it can be controlled. Disc galaxies in which the orbital speed does not…
Using high resolution N-body simulations of stellar disks embedded in cosmologically motivated dark matter halos, we study the evolution of bars and the transfer of angular momentum between halos and bars. We find that dynamical friction…
The well-known bar instability of rotationally-supported disk galaxy models has been studied extensively since its first discovery over half a century ago. We were therefore very surprised to find cases of disks embedded in rigid halos,…
We investigate the effect of rotating, triaxial halos on disk galaxies through an extensive set of numerical N-body simulations. Our simulations use a rigid potential field for the halos and bulges and collisionless particles for the disks.…
The characteristics of the galactic bars that are prone to suffer a damaging impact from a massive central black hole are examined using flat stellar disks. We construct three disk model groups that consist of exponential disks with one…
The secular evolution of disk galaxies is largely driven by resonances between the orbits of 'particles' (stars or dark matter) and the rotation of non-axisymmetric features (spiral arms or a bar). Such resonances may also explain kinematic…
The spin of dark halos has been shown to significantly affect bar formation and evolution in disk galaxies. To understand the physical role of the halo spin on bar formation, we run $N$-body simulations of isolated, Milky Way-sized galaxies…
Barred galaxies constitute about two thirds of observed disc galaxies. Bars affect not only the mass distribution of gas and stars, but also that of the dark matter. An elongation of the inner dark matter halo is known as the halo bar. We…
We study the shape and kinematics of simulated dwarf galaxy discs in the APOSTLE suite of $\Lambda$CDM cosmological hydrodynamical simulations. We find that a large fraction of these gas-rich, star-forming discs show weak bars in their…
When bars form within galaxy formation simulations in the standard cosmological context, dynamical friction with dark matter (DM) causes them to rotate rather slowly. However, almost all observed galactic bars are fast in terms of the ratio…
In order to address the question of whether spiral disturbances in galaxy discs are gravitationally coupled to the halo, we conduct simulations of idealized models of disc galaxies. We compare growth rates of spiral instabilities in…