相关论文: Fugitive stars in active galaxies
Implementing the Generalized Alignment Index (GALI) method of chaos detection we investigate the dynamical behavior of the nonlinear disordered Klein-Gordon lattice chain in one spatial dimension. By performing extensive numerical…
The actual mechanism(s) powering galactic outflows in active galactic nuclei (AGN) is still a matter of debate. At least two physical models have been considered in the literature: wind shocks and radiation pressure on dust. Here we provide…
Stellar population and stellar kinematic studies provide unique but complementary insights into how galaxies build-up their stellar mass and angular momentum. A galaxy's mean stellar age reveals when stars were formed, but provides little…
We examine the escape from the four hill potential by using the method of grid classification, when polar coordinates are used for expressing the initial conditions of the orbits. In particular, we investigate how the energy of the orbits…
Dynamical interactions between colliding spiral galaxies strongly affect the state and distribution of their interstellar gas. Observations indicate that interactions funnel gas toward the nuclei, fueling bursts of star formation and…
Spontaneous persistent motions driven by active processes play a central role to maintain the living cells far from equilibrium. In the majority of the research works, the steady state dynamics of an active system has been described in…
Observations of the interstellar medium are key to deciphering the physical processes regulating star formation in galaxies. However, observational uncertainties and detection limits can bias the interpretation unless carefully modeled.…
An axially symmetric galactic gravitational model composed of a dense, massive and spherical nucleus with an additional dark matter halo component was used, to distinguish between the regular and chaotic character of orbits of stars that…
Compact elliptical galaxies form a rare class of stellar system (~30 presently known) characterized by high stellar densities and small sizes and often harboring metal-rich stars. They were thought to form through tidal stripping of massive…
The pattern speeds of spiral galaxies are closely related to the flow of material in their disks. Flows that follow the `precessing ellipses' paradigm (see e.g., Kalnajs 1973) are likely associated with slowly rotating spirals, which have…
The interstellar dust content in galaxies can be traced in extinction at optical wavelengths, or in emission in the far-infrared. Several studies have found that radiative transfer models that successfully explain the optical extinction in…
A matrix method is formulated in a Lagrangian representation for the solution of the characteristic value problem governing modes of oscillation and instability in a collisionless stellar system. The underlying perturbation equations govern…
Runaway stars depart their birthplaces with high peculiar velocities. Two mechanisms are commonly invoked to explain their origin, the binary supernova scenario (BSS) and the dynamical ejection scenario (DES). Investigating the kinematic…
Galactic winds and mass outflows are observed both in nearby starburst galaxies and in high-redshift star-forming galaxies. In this paper we develop a simple analytic model to understand the observed superwind phenomenon. Our model is built…
Two mathematical models of three bodies of variable masses are used to obtain a qualitative description of two interacting galaxies with mass exchange and mass loss. The reference system is centred on the largest body (the most massive…
Various lattice gas automata have been proposed in the past decades to simulate physics and address a host of problems on collective dynamics arising in diverse fields. In this work, we employ the lattice gas model defined on the sphere to…
We study the flow of gas in a barred-galaxy model, in which a considerable part of the underlying stable periodic orbits have loops where, close to the ends of the bar, several orbital families coexist and chaos dominates. Such conditions…
Formulation of the Lagrangian approach is presented for studying features of motions of stellar bodies with non-zero rest mass in the vicinity of fast-spinning black holes. The structure of Lagrangian is discussed. The general method is…
We report new constraints on the local escape speed of our Galaxy. Our analysis is based on a sample of high velocity stars from the RAVE survey and two previously published datasets. We use cosmological simulations of disk galaxy formation…
In a series of papers, we propose a theory to explain the formation and properties of rings and spirals in barred galaxies. The building blocks of these structures are orbits guided by the manifolds emanating from the unstable Lagrangian…