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Related papers: The Pattern Speed of the Galactic Bar

200 papers

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 compare distance resolved, absolute proper motions in the Milky Way bar/bulge region to a grid of made-to-measure dynamical models with well defined pattern speeds. The data are obtained by combining the relative VVV Infrared Astrometric…

Astrophysics of Galaxies · Physics 2022-04-29 Jonathan Clarke , Ortwin Gerhard

We study, using direct orbit integrations, the kinematic response of the outer stellar disk to the presence of a central bar, as in the Milky-Way. We find that the bar's outer Lindblad resonance (OLR) causes significant perturbations of the…

Astrophysics · Physics 2007-05-23 Gerhard M"uhlbauer , Walter Dehnen

The method to study oscillating potentials of double bars, based on invariant loops, is introduced here in a new way, intended to be more intelligible. Using this method, I show how the orbital structure of a double-barred galaxy (nested…

Astrophysics of Galaxies · Physics 2009-03-17 Witold Maciejewski

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 present measurements of the stellar and gaseous velocities in the central 5' of the Local Group spiral M33. The data were obtained with the ARC 3.5m telescope. Blue and red spectra with resolutions from 2 to 4\AA covering the principal…

Astrophysics · Physics 2009-11-13 Edvige Corbelli , Rene' A. M. Walterbos

Detailed analysis of kinematics of the Milky Way disk in the solar neighborhood based on the GAIA DR3 catalog reveals the existence of peculiarities in the stellar velocity distribution perpendicular to the galactic plane. We study the…

Astrophysics of Galaxies · Physics 2023-10-17 Vladimir Korchagin , Artem Lutsenko , Roman Tkachenko , Giovanni Carraro , Katherine Vieira

The nature of our Milky Way Galaxy is reexamined from an eclectic point of view. Evidence for a central bar, for example, is not reflected in the distribution of RR Lyrae variables in the central bulge [4,5], and it is not clear if either a…

Astrophysics of Galaxies · Physics 2015-06-17 David G. Turner

Non-axisymmetries in the Galactic potential (spiral arms and bar) induce kinematic groups such as the Hercules stream. Assuming that Hercules is caused by the effects of the Outer Lindblad Resonance of the Galactic bar, we model…

To estimate the peculiar velocity of the Sun with respect to the Local Standard of Rest (LSR), we used young objects in the Solar neighborhood with distance measurement errors within 10%-15%. These objects were the nearest Hipparcos stars…

Astrophysics of Galaxies · Physics 2018-03-14 V. V. Bobylev , A. T. Bajkova

We compare stellar orbits in an early (NGC 4314) and a late-type barred galaxy (NGC 1073). We find that these bars are cold in the sense that the majority of stars can be described as being nearby to periodic orbits. We place limits of…

Astrophysics · Physics 2007-05-23 A. C. Quillen

Galactic bars are found in the majority of disc galaxies. They rotate nearly rigidly with an angular frequency called pattern speed. Previous idealised simulations have shown that bar pattern speed decreases with time due to dynamical…

Astrophysics of Galaxies · Physics 2024-12-11 Marcin Semczuk , Walter Dehnen , Ralph Schönrich , E. Athanassoula

The distribution of moving groups in the solar neighborhood has been used to constrain dynamical properties of the Milky Way for decades. The kinematic bimodality between the main mode (Hyades, Pleiades, Coma Berenices, and Sirius) and…

Astrophysics of Galaxies · Physics 2024-04-09 Scott Lucchini , Elena D'Onghia , J. Alfonso L. Aguerri

This paper describes test particle simulations of the response of the outer parts of Galactic disks to barring and spiral structure. Simulations are conducted for cold Mestel disks and warm quasi-exponential disks with completely flat…

Astrophysics · Physics 2009-11-10 Dalia Chakrabarty

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

We have studied a sample containing about 6000 OB stars with proper motions and trigonometric parallaxes from the Gaia DR2 catalogue. The following parameters of the angular velocity of Galactic rotation have been found:…

Astrophysics of Galaxies · Physics 2019-06-26 V. V. Bobylev , A. T. Bajkova

We consider three samples of O- and B-type stars from the solar neighborhood 0.6--4 kpc for which we have taken the distances, line-of-sight velocities, and proper motions from published sources. The first sample contains 120 massive…

Astrophysics of Galaxies · Physics 2015-07-30 V. V. Bobylev , A. T. Bajkova

It has been suggested that a resonance between a rotating bar and stars in the solar neighbourhood can produce the so called 'Hercules stream'. Recently, a second bar may have been identified in the Galactic centre, the so called 'long…

Astrophysics of Galaxies · Physics 2010-05-25 Esko Gardner , Chris Flynn

Does the environment of a galaxy directly influence the kinematics of its bar? We present observational evidence that bars in high-density environments exhibit significantly slower rotation rates than bars in low-density environments.…

Astrophysics of Galaxies · Physics 2026-03-18 Natalia Puczek , Tobias Géron , Rebecca J. Smethurst , Chris J. Lintott

Context. An accurate estimate of the local standard of rest (LSR) is required to determine key parameters used in approximate galactic mass models and to understand Galactic structure and evolution. However, authors are often forced to base…

Astrophysics · Physics 2009-04-21 Charles Francis , Erik Anderson