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Related papers: Direct measurements of bar pattern speeds

200 papers

Previous work has related the Galactic Bar to structure in the local stellar velocity distribution. Here we show that the Bar also influences the spatial gradients of the velocity vector via the Oort constants. By numerical integration of…

Astrophysics · Physics 2009-11-13 I. Minchev , J. Nordhaus , A. C. Quillen

We construct a large set of dynamical models of the galactic bulge, bar and inner disk using the Made-to-Measure method. Our models are constrained to match the red clump giant density from a combination of the VVV, UKIDSS and 2MASS…

Astrophysics of Galaxies · Physics 2016-12-21 Matthieu Portail , Ortwin Gerhard , Christopher Wegg , Melissa Ness

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…

Astrophysics · Physics 2009-11-13 Dalia Chakrabarty

The dynamical stability and evolution of disc galaxies with different disc thickness as well as various fraction and concentration of stellar counter-rotation is investigated with self-consistent numerical simulations. In particular,…

Astrophysics · Physics 2007-05-23 D. Friedli

We introduce a new approach to classify barred galaxies that utilizes the transverse-to-radial force ratio map (ratio map, hereafter) in a different manner from previous studies. When we display the ratio map in polar coordinates, barred…

Astrophysics of Galaxies · Physics 2020-08-26 Yun Hee Lee , Myeong-Gu Park , Hong Bae Ann , Taehyun Kim , Woo-Young Seo

We use Schwarzschild's orbit-superposition technique to construct self-consistent models of the Galactic bar. Using $\chi^2$ minimisation, we find that the best-fit Galactic bar model has a pattern speed $\Omega_{\rm p}=60 \rm{km s^{-1}…

Astrophysics of Galaxies · Physics 2015-06-11 Yougang Wang , Hongsheng Zhao , Shude Mao , R. M. Rich

Direct measurements of the stellar magnetic fields are based on the splitting of spectral lines into polarized Zeeman components. With few exceptions, Zeeman signatures are hidden in data noise and a number of methods have been developed to…

We analyze optical and near-infrared data of a sample of 11 barred spiral galaxies, in order to establish a connection between star formation and bar/spiral dynamics. We find that 22 regions located in the bars, and 20 regions in the spiral…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Eric E. Martínez-García , Rosa A. González-Lópezlira

We present a study of the effect of bulge mass on the evolution of bar pattern speed in isolated disk galaxies using N-body simulations. Earlier studies have shown that disk stars at the inner resonances can transfer a significant amount of…

Astrophysics of Galaxies · Physics 2020-01-08 Sandeep Kumar Kataria , Mousumi Das

We analyse new integral field spectroscopy of the inner region (central 2.5 kpc) of the spiral galaxy NGC 4321 to study the peculiar kinematics of this region. Fourier analysis of the velocity residuals obtained by subtracting an…

Astrophysics · Physics 2009-11-13 A. Castillo-Morales , J. Jimenez-Vicente , E. Mediavilla , E. Battaner

Galactic bars can form via the internal bar instability or external tidal perturbations by other galaxies. We systematically compare the properties of bars formed through the two mechanisms with a series of controlled $N$-body simulations…

Astrophysics of Galaxies · Physics 2024-12-09 Yirui Zheng , Juntai Shen

Dark gaps, low surface brightness regions along the bar minor axis, are expected to form as a consequence of secular evolution in barred galaxies. Although several studies have proposed links between dark gap locations and dynamical…

Astrophysics of Galaxies · Physics 2025-10-14 Taehyun Kim , Dimitri A. Gadotti , Myeong-gu Park , Yun Hee Lee , Francesca Fragkoudi , Minjin Kim , Woong-Tae Kim

Present in over 45% of local spirals, boxy and peanut-shaped bulges are generally interpreted as edge-on bars and may represent a key phase in the evolution of bulges. Aiming to test such claims, the kinematic properties of self-consistent…

Astrophysics · Physics 2009-11-10 M. Bureau , E. Athanassoula

The relative bar torques for 45 galaxies observed at $K$- band with the 4.2m William Herschel Telescope are determined by transforming the light distributions into potentials and deriving the maximum ratios of the tangential forces relative…

Astrophysics · Physics 2009-11-06 D. L. Block , I. Puerari , J. H. Knapen , B. G. Elmegreen , R. Buta , S. Stedman , D. M. Elmegreen

The arguments in favor of the unified formation mechanism for both slow (Lynden-Bell's) bars and common fast bars are given. This mechanism consists in a certain instability that is akin to the well-known radial orbit instability; it is…

Astrophysics · Physics 2007-05-23 E. V. Polyachenko , V. L. Polyachenko

Using the potential from N-body simulations, we construct the Galactic bar models with the Schwarzschild method. By varying the pattern speed and the position angle of the bar, we find that the best-fit bar model has pattern speed…

Astrophysics of Galaxies · Physics 2015-06-16 Yougang Wang , Shude Mao , Richard J. Long , Juntai Shen

The observed velocities of the gas in barred galaxies are a combination of the azimuthally-averaged circular velocity and non-circular motions, primarily caused by gas streaming along the bar. These non-circular flows must be accounted for…

Astrophysics of Galaxies · Physics 2015-10-28 Toky Randriamampandry , Francoise Combes , Claude Carignan , Nathan Deg

We test the theoretical prediction that the straightest dust lanes in bars are found in strongly barred galaxies, or more specifically, that the degree of curvature of the dust lanes is inversely proportional to the strength of the bar. The…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Sebastien Comeron , Inma Martinez-Valpuesta , Johan H. Knapen , John E. Beckman

Stellar kinematics provide a window into the gravitational field, and therefore into the distribution of all mass, including dark matter. Deep Potential is a method for determining the gravitational potential from a snapshot of stellar…

Astrophysics of Galaxies · Physics 2023-10-03 Taavet Kalda , Gregory M. Green , Soumavo Ghosh

Results from the modelling of bars in nearly 300 galaxies are used to test predictions from theoretical work on the evolution of bars. Correlations are found between bar ellipticity and boxiness, between bar strength and normalised size,…

Astrophysics · Physics 2008-11-27 Dimitri A. Gadotti