相关论文: Order and Chaos in the Local Disc Stellar Kinemati…

(Abridged) The Galactic bar causes a characteristic splitting of the disc phase space into regular and chaotic orbit regions which is shown to play an important role in shaping the stellar velocity distribution in the Solar neighbourhood. A…

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…

From the tangential velocities of stars all over the sky, one can, in a statistical way, infer their 3D velocity distribution. An application to Hipparcos data reveals rich structure in the planar stellar motions: there are several moving…

We examine the idea that dynamical parameters can be estimated by identifying locations in the solar neighbourhood where simulated velocity distributions match the observed local distribution. Here, the dynamical influence of both the…

We study the kinematics of a local sample of stars, located within a cylinder of 500 pc radius centered on the Sun, in the RAVE dataset. We find clear asymmetries in the $v_R$-$v_\phi$ velocity distributions of thin and thick disk stars:…

We use about 15,000 F/G nearby dwarf stars selected from the LAMOST pilot survey to map the U-V velocity distribution in the solar neighbourhood. An extreme deconvolution algorithm is applied to reconstruct an empirical multi-Gaussian…

A high-resolution N-body simulation suggests that stellar streams in the discs of barred galaxies are common and strongly time-dependent. The velocity distribution of stars in the Solar neighbourhood betray many such streams, including a…

We perform numerical simulations of a stellar galactic disk with initial conditions chosen to represent an unrelaxed population which might have been left following a merger. Stars are unevenly distributed in radial action angle, though the…

We characterize empirically the radial diffusion of stars in the plane of a typical barred disk galaxy by calculating the local spatial diffusion coefficient and diffusion time-scale for bulge-disk-halo N-body self-consistent systems which…

An N-body hybrid simulation, integrating both massive and tracer particles, of a Galactic disk is used to study the stellar phase space distribution or velocity distributions in different local neighborhoods. Pattern speeds identified in…

Using available kinematical data for a subsample of NLTT stars from the HIPPARCOS mission we confirm the existence of a previously reported local anomaly in the (u,v) plane: the mean motion u for old disc stars, with v < -30 km/s, is…

We attempt to understand the state of the local phase space by comparing simulated 2-D velocity distributions to the distribution that is constructed for the solar neighbourhood, from measurements of stellar radial and transverse…

Following Tancredi, Sanchez and Roig (2001)'s criteria of chaos, two ways of setting initial velocities are used in the numerical surveys to explore the possible chaotic and regular orbits for the disc-star-planet systems. We find that the…

Aims: To study the imprints of a rotating bar on the kinematics of stars in the thin and thick disks throughout the Galaxy. Methods: We perform test particle numerical simulations of the thin and thick disks in a 3D Galactic potential that…

Many of the Milky Way's accreted substructures have been discovered and studied in the space of energy $E$, and angular momentum components $L_z$ and $L_{\bot}$. In a static axisymmetric system, these quantities are (reasonable…

The paper is devoted to the analysis of the influence of the galactic bar on the nature of the orbital motion (chaotic or regular) of globular clusters in the central region of the Galaxy with a radius of 3.5 kpc, which are subject to the…

Recent analysis of stellar populations in barred galaxies have focused on the spatial distribution of stellar population ages and metallicities. However, barred galaxies are complex objects where dynamical instabilities play a leading role…

We study the role of asymptotic curves in supporting the spiral structure of a N-body model simulating a barred spiral galaxy. Chaotic orbits with initial conditions on the unstable asymptotic curves of the main unstable periodic orbits…

We investigate the evolution of the relative angle between the stellar rotation axis and the circumstellar disc axis of a star that forms in a stellar cluster from the collapse of a turbulent molecular cloud. This is an inherently chaotic…

Many of the stars in the Galaxy were formed in binary systems. The widest of these can eventually become disrupted due to a combination of kicks from passing stars and the Galactic tidal field. If the Galactic disk were purely axisymmetric,…