English
Related papers

Related papers: Measuring bar pattern speeds from single simulatio…

200 papers

We analyze how the orbital support of the inner bar in a double-barred galaxy (nested bars) depends on the angular velocity (i.e. pattern speed) of this bar. We study orbits in seven models of double bars using the method of invariant…

Astrophysics of Galaxies · Physics 2015-05-19 Witold Maciejewski , Emma E. Small

Based on a high quality $N$-body simulation of a double bar galaxy model, we investigate the evolution of the bar properties, including their size, strength and instantaneous pattern speed derived by using three distinct methods: the…

Astrophysics of Galaxies · Physics 2018-07-11 Yu-Ting Wu , Daniel Pfenniger , Ronald E. Taam

The MaNGA project has obtained IFU data for several thousand nearby galaxies, including barred galaxies. With the two dimensional spectral and kinematic information provided by IFUs, we can measure the pattern speed of a barred galaxy,…

Astrophysics of Galaxies · Physics 2018-10-17 Rui Guo , Shude Mao , E. Athanassoula , Hongyu Li , Junqiang Ge , R. J. Long , Michael Merrifield , Karen Masters

The bar pattern speed ($\Omega_{\rm b}$) is defined as the rotational frequency of the bar, and it determines the bar dynamics. Several methods have been proposed for measuring $\Omega_{\rm b}$. The non-parametric method proposed by…

A unified definition for the rotation angle and rotation angular speed of general beams, including those with orbital angular momentum (OAM), has been lacking until now. The rotation of a general beam is characterized by observing the…

Optics · Physics 2024-11-13 Zhen-Xiang Hao , Ruo-Xi Wu , Hong-Bo Jin , Ya-Zheng Tao , Yue-Liang Wu

We present detailed numerical simulations of NGC 1433, an intermediate-type barred spiral showing strong morphological features including a secondary bar, nuclear ring, inner ring, outer pseudoring, and two striking, detached spiral arcs…

Astrophysics · Physics 2009-11-13 P. Treuthardt , H. Salo , P. Rautiainen , R. Buta

More than 10% of the barred galaxies with a direct measurement of the bar pattern speed host an ultrafast bar. These bars extend beyond the corotation radius and challenge our understanding of the orbital structure of barred galaxies. Most…

An important dynamic parameter of barred galaxies is the bar pattern speed. Among several methods that are used for the determination of the pattern speed the Tremaine-Weinberg method has the advantage of model independency and accuracy. In…

Astrophysics of Galaxies · Physics 2010-08-30 R. F. Gabbasov , P. Repetto , M. Rosado

It is well known that estimating the pairwise velocity of galaxies, v_{12}, from the redshift space galaxy correlation function is difficult because this method is highly sensitive to the assumed model of the pairwise velocity dispersion.…

Astrophysics · Physics 2009-10-31 P. G. Ferreira , R. Juszkiewicz , H. A. Feldman , M. Davis , A. H. Jaffe

This paper presents a method for determining spacecraft angular rates using event-based camera sensing. This is achieved by analyzing the temporal distribution of brightness events triggered by the apparent motion of stars. The location and…

Systems and Control · Electrical Eng. & Systems 2025-12-16 Vittorio Franzese , Matteo El Hariry

We consider a measurement of the position of a spot painted on the surface of a trapped nano-optomechanical sphere. The measurement extracts information about the position of the spot and in doing so measures a combination of the…

Quantum Physics · Physics 2016-10-03 Jason F. Ralph , Kurt Jacobs , Jonathon Coleman

Pattern speeds are a fundamental parameter of the dynamical features (e.g. bars, spiral arms) of a galaxy, setting resonance locations. Pattern speeds are not directly observable, so the Tremaine-Weinberg (TW) method has become the most…

Astrophysics of Galaxies · Physics 2023-07-19 Olga Borodina , Thomas G. Williams , Mattia C. Sormani , Sharon Meidt , Eva Schinnerer

Most secular effects produced by stellar bars strongly depend on the pattern speed. Unfortunately, it is also the most difficult observational parameter to estimate. In this work, we measured the bar pattern speed of 97 Milky-Way Analogue…

We present a review on bar pattern speeds from preliminary results in the context of the Nuclei of Galaxies (NUGA) project. The large variety of molecular circumnuclear morphologies found in NUGA is a challenging result that implies the…

This paper examines the reliability of the Tremaine-Weinberg (TW) method in measuring the pattern speed of barred galaxies at high redshifts. Measuring pattern speeds at high redshift may help to shed light on the time evolution of…

The Tremaine-Weinberg (TW) method and its variations provide the most direct means to measure the pattern speeds of galactic bars. We establish a unifying framework by deriving an integral form of the continuity equation over an arbitrary…

Astrophysics of Galaxies · Physics 2026-04-10 Hangci Du , Yougang Wang , Junqiang Ge , Rui Guo

We measure and compare the pattern speeds of vertical breathing, vertical bending, and spiral density waves in two isolated N-body+SPH simulations, using windowed Fourier transforms over 1 Gyr time intervals. We show that the pattern speeds…

We present MUSE integral field stellar and ionized velocity maps for a sample of 14 barred galaxies. Most of these objects exhibit "S"-shape iso-velocities in the bar region indicative of the presence of streaming motions in the velocity…

Spatial intensity moments computed on images can be used as a probe of the centroid, size, and orientation of pixelized sources such as stars and galaxies. However, all measurements made on images suffer from errors due to undersampling and…

Instrumentation and Methods for Astrophysics · Physics 2020-12-11 Andrew K. Bradshaw

We report on our attempts to achieve a nearly steady-state gas flow in hydrodynamical simulations of doubly barred galaxies. After exploring the parameter space, we construct two models, for which we evaluate the photometric and the…

Astrophysics · Physics 2008-01-10 Witold Maciejewski , Hannah Singh