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Related papers: Direct measurements of bar pattern speeds

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The very first results of the application of the Tremaine-Weinberg (hereafter TW) method on Halpha velocity fields are presented to find pattern speeds of galaxies. The technique is used for a sample of four barred galaxies(NGC4321,…

Astrophysics · Physics 2019-08-15 O. Hernandez , C. Carignan , P. Amram , and O. Daigle

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…

Astrophysics · Physics 2009-11-10 Richard J. Rand , John F. Wallin

We present surface photometry and stellar kinematics of a sample of 5 SB0 galaxies: ESO 139-G009, IC 874, NGC 1308, NGC 1440 and NGC 3412. We measured their bar pattern speed using the Tremaine-Weinberg method, and derived the ratio, R, of…

Astrophysics · Physics 2009-11-07 J. A. L. Aguerri , V. P. Debattista , E. M. Corsini

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…

Astrophysics of Galaxies · Physics 2015-05-13 Sharon E. Meidt , Richard J. Rand , Michael R. Merrifield

Estimating the bar pattern speed (\Om{}) is one of the main challenges faced in understanding the role of stellar bars in galaxy dynamical evolution. This work aims to characterise different uncertainty sources affecting the Tremaine…

When integrals in the standard Tremaine-Weinberg method are evaluated for the case of a realistic model of a doubly barred galaxy, their modifications introduced by the second rotating pattern are in accord with what can be derived from a…

Astrophysics · Physics 2009-11-11 Witold Maciejewski

I show that Tremaine-Weinberg (TW) measurements of bar pattern speeds are sensitive to errors in the position angle of the disc, PA_disc. I use an $N$-body experiment to measure these errors; for typical random PA_disc errors, the resulting…

Astrophysics · Physics 2009-11-10 Victor P. Debattista

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 have used the Tremaine-Weinberg method to measure the angular speed of rotation for the bar in the SB0 galaxy NGC 936. With this technique, the bar's pattern speed, Omega_p, can be derived from the luminosity and stellar-kinematic…

Astrophysics · Physics 2015-06-24 Michael R. Merrifield , Konrad Kuijken

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…

Astrophysics of Galaxies · Physics 2016-07-20 Jason C. Speights , Paul C. Rooke

A significant fraction of barred spiral galaxies exhibits peanut/X-shaped structures in their central regions. Bars are known to rotate with a single pattern speed, and they eventually slow down over time due to the dynamical friction with…

Astrophysics of Galaxies · Physics 2021-05-10 Pavan Vynatheya , Kanak Saha , Soumavo Ghosh

Using a dataset of stars from a barred galaxy that provides instantaneous positions and velocities in the sky, we propose a method to identify its key structures, such as the central bar and spiral arms, and to determine the bar pattern…

Astrophysics of Galaxies · Physics 2025-06-24 P. Sánchez-Martín , J. Amorós , J. J. Masdemont

We test the idea that bar pattern speeds decrease with time owing to angular momentum exchange with a dark matter halo. If this process actually occurs, then the locations of the corotation resonance and other resonances should generally…

Astrophysics of Galaxies · Physics 2022-02-23 Yun Hee Lee , Myeong-Gu Park , Ho Seong Hwang , Hong Bae Ann , Haeun Chung , Taehyun Kim

We describe methods to measure simultaneously the orientation angle $\psi$ and pattern speed $\Omega$ from single snapshots of simulated barred galaxies. Unlike previous attempts, our approach is unbiased, precise, and consistent in the…

Astrophysics of Galaxies · Physics 2022-11-16 Walter Dehnen , Marcin Semczuk , Ralph Schoenrich

We study the bar pattern speeds and corotation radii of 225 barred galaxies, using IFU data from MaNGA and the Tremaine-Weinberg method. Our sample, which is divided between strongly and weakly barred galaxies identified via Galaxy Zoo, is…

Density waves in galaxy disks have been proposed over the years, in a variety of specific models, to explain spiral arm structure and its relation to the mass distribution, notably in barred galaxies. An important parameter in dynamical…

Astrophysics of Galaxies · Physics 2018-03-14 John E. Beckman , Joan Font , Alejandro Borlaff , Begoña García-Lorenzo

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…

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…

Astrophysics · Physics 2016-08-30 S. E. Meidt , R. J. Rand

Simulations predict that bars in galaxies should slow down over time. This is often attributed to the exchange of angular momentum between the bar and other regions of the galaxy, such as the outer disc and dark matter halo, which implies…

Astrophysics of Galaxies · Physics 2026-04-07 Tobias Géron , Kai Zhu , Steph Campbell , Chris Lintott , R. J. Smethurst , Behzad Tahmasebzadeh

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