相关论文: Secular evolution and cylindrical rotation in boxy…

We present the results of a series of numerical simulations aimed to study the evolution of a disc galaxy within the global tidal field of a group environment. Both the disc galaxy and the group are modelled as multi-component,…

The structure and evolution of the stellar velocity ellipsoid plays an important role in shaping galaxies undergoing bar driven secular evolution and the eventual formation of a boxy/peanut bulge such as present in the Milky Way. Using…

We present a comprehensive series of $N$-body as well as $N$-body + SPH simulations to study the secular evolution of the structure of disk galaxies. Our simulations are organized in a hierarchy of increasing complexity, ranging from…

Boxy edge-on profiles can be accounted for not only in models of barred galaxies, but also in models of normal (non-barred) galaxies. Thus, the presence of a bar is not a sine qua non condition for the appearance of this feature, as often…

A vertical metallicity gradient in the Milky Way bulge is well-established. Yet, its origin has not been fully understood under the Galactic secular evolution scenario. We construct single-disk and triple-disk $N$-body models with an…

We examine the dependence of the fraction of galaxies containing pseudo bulges on environment for a flux limited sample of $\sim$5000 SDSS galaxies. We have separated bulges into classical and pseudo bulge categories based on their position…

Through vertical resonances, bars can produce pseudo-bulges, within secular evolution. Bulges and pseudo-bulges have doubled their mass since z=1. The frequency of bulge-less galaxies at z=0 is difficult to explain, especially since clumpy…

Secular evolution gradually shapes galaxies by internal processes, in contrast to early cosmological evolution which is more rapid. An important driver of secular evolution is the flow of gas from the disk into the central regions, often…

It has been known for some time that the Milky Way is a barred disk galaxy. More recently several studies inferred from starcount observations that the Galaxy must contain a separate, new, flat long bar component, twisted relative to the…

Stellar bars are important internal drivers of secular evolution in disk galaxies. Using a sample of nearby spiral galaxies with weak and strong bars, we explore the relationships between the star formation feature and stellar bars in…

We examine the effects that the modelling of a Boxy/Peanut (B/P) bulge will have on the estimates of the stellar gravitational potential, forces, orbital structure and bar strength of barred galaxies. We present a method for obtaining the…

It has been suggested that the peanut-shaped bulges seen in some edge-on disk galaxies are produced when bars in these galaxies buckle. This paper reviews the modelling which seeks to show how bars buckle, and I present a very simple new…

Bulges can be classified into classical and pseudobulges; the former are considered to be end products of galactic mergers and the latter to form via secular evolution of galactic disks. Observationally, bulges of disk galaxies are mostly…

It is usually thought that viscous torque works to align a circumbinary disk with the binary's orbital plane. However, recent numerical simulations suggest that the disk may evolve to a configuration perpendicular to the binary orbit…

Galactic bars induce characteristic motions deviating from pure circular rotation, known as non-circular motions. As bars are non-axisymmetric structures, stronger bars are expected to show stronger non-circular motions. However, this has…

Boxy, peanut- or X-shaped "bulges" are observed in a large fraction of barred galaxies viewed in, or close to, edge-on projection, as well as in the Milky Way. They are the product of dynamical instabilities occurring in stellar bars, which…

Bars in galaxies may develop through a global instability or due to an interaction with another system. We study bar formation in disky dwarf galaxies orbiting a Milky Way-like galaxy. We employ $N$-body simulations to study the impact of…

Major-axis long-slit stellar kinematics was obtained for 30 edge-on spiral galaxies, 24 with a boxy/peanut-shaped (B/PS) bulge. B/PS bulges are present in >45% of highly inclined systems and much work suggests that they are the edge-on…

It was argued in the past that bulges of galaxies cannot be formed through collisionless secular evolution because that would violate constraints on the phase-space density: the phase-space density in bulges is several times larger than in…

Bulges are commonly believed to form in the dynamical violence of galaxy collisions and mergers. Here we model the stellar kinematics of the Bulge Radial Velocity Assay (BRAVA), and find no sign that the Milky Way contains a classical bulge…