相关论文: Measuring bar pattern speeds from single simulatio…
We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, over imposed on the axisymmetric components in the plane of the…
Most galaxies have a warped shape when they are seen from an edge-on point of view. The reason for this curious form is not completely known so far and in this work we apply dynamical system tools to contribute to its explanation. Starting…
We derive a novel efficient scheme to measure the rate constant of transitions between stable states separated by high free energy barriers in a complex environment within the framework of transition path sampling. The method is based on…
Current theories of spiral and bar structure predict a variety of pattern speed behaviors, calling for detailed, direct measurement of the radial variation of pattern speeds. Our recently developed Radial Tremaine-Weinberg (TWR) method…
Orientation estimation is a fundamental task in 3D shape analysis which consists of estimating a shape's orientation axes: its side-, up-, and front-axes. Using this data, one can rotate a shape into canonical orientation, where its…
Radially self-accelerating light exhibits an intensity pattern that describes a spiraling trajectory around the optical axis as the beam propagates. In this article, we show in simulation and experiment how such beams can be used to perform…
The experiment proposed aims to evidence and to measure the deflection of light rays induced by the source speed upon emission, and to discern it from the aberration of light rays induced by the observer speed. The method stands in creating…
In this paper we show explicit and direct relations between the expected quantities and the observed quantities for the components of Galactic superluminal sources. Basic formulas for calculating the real speed and the angle to the line of…
Our recent studies of axial-symmetry breaking in the nearby ($d <3 \,{\rm kpc}$) star counts are sensitive to the distortions of stellar orbits perpendicular and parallel to the orientation of the bar just within and beyond the outer…
Although at least one quarter of early-type barred galaxies host secondary stellar bars embedded in their large-scale primary counterparts, the dynamics of such double barred galaxies are still not well understood. Recently we reported…
We present a 3D Bayesian method to model the kinematics of strongly lensed galaxies from spatially-resolved emission-line observations. This technique enables us to simultaneously recover the lens-mass distribution and the source kinematics…
Spiral galaxies displaying molecule-dominated ISMs are potential candidates for pattern speed determination by the Tremaine-Weinberg (TW) method (1984); the molecular gas of such galaxies, as traced by CO emission, is argued to…
A co-rotation radius is a key characteristic of disc galaxies that is essential to determine the angular speed of the spiral structure $\Omega_{p}$, and therefore understand its nature. In the literature, there are plenty of methods to…
Theories that attempt to explain the dynamical relationship between bar and spiral patterns in galactic disks make different predictions about the radial profile of the pattern speed. These are tested for the H-alpha bar and spiral patterns…
To study the peculiarities of the Galactic spiral density wave, we have analyzed the space velocities of Galactic Cepheids with proper motions from the Hipparcos catalog and line-of-sight velocities from various sources. First, based on the…
We report Very Large Array B-configuration observations of the atomic hydrogen 21 cm line emission from the barred disk galaxy NGC 5597 at an angular resolution of 7.1" x 4.2". Using the resonance method, and assuming the ratio of the…
We apply the Tremaine-Weinberg method of pattern speed determination to data cubes of CO emission in six spiral galaxies from the BIMA SONG survey each with an ISM dominated by molecular gas. We compare derived pattern speeds with estimates…
We presented a new method for measuring the squares of the amplitudes and phases of partial vortex-beams in a complex beam array in real time. The method is based on measuring the high-order intensity moments and analyzing the solutions of…
Extreme speed profiles, that are impossible to anayze correctly using the usual methods, are shown to be easily handled using the methods developed previously by Nicholson (astro-ph/0006330). These profiles are constant orbital speeds with…
We present a new empirical model for galaxy rotation curves that introduces a velocity correction term {\omega}, derived from observed stellar motion and anchored to Keplerian baselines. Unlike parametric halo models or modified gravity…