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Related papers: Measuring the dynamical length of galactic bars

200 papers

The integrated 21 cm H I emission profile of a galaxy encodes valuable information on the kinematics, spatial distribution, and dynamical state of its cold interstellar medium. The line width, in particular, reflects the rotation velocity…

Astrophysics of Galaxies · Physics 2020-08-05 Niankun Yu , Luis C. Ho , Jing Wang

Resonant torques couple stellar bars to dark matter halos. Here we use high-resolution numerical simulations to demonstrate long-term angular momentum transfer between stellar bars and dark matter orbits of varying orientation. We show that…

Astrophysics of Galaxies · Physics 2021-07-07 Angela Collier , Ann-Marie Madigan

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

We provide the first quantitative evidence for the deceleration of the Galactic bar from local stellar kinematics in agreement with dynamical friction by a typical dark matter halo. The kinematic response of the stellar disk to a…

Astrophysics of Galaxies · Physics 2023-08-04 Rimpei Chiba , Jennifer K. S. Friske , Ralph Schönrich

An analysis of the NICMOS Deep Field shows that there is no evidence of a decline in the bar fraction beyond z~0.7, as previously claimed; both bandshifting and spatial resolution must be taken into account when evaluating the evolution of…

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

Recent GLIMPSE data have further confirmed the hypothesis of the existence of an in-plane long bar different from the bulge of the Milky Way with the same characteristics as emphasized some years ago by our team. In this paper, we present…

The Galactic kinematics of Mira variables have been studied using infrared photometry, radial velocities, and Hipparcos parallaxes and proper motions. For Miras in the period range 145 to 200 days (probably corresponding to [Fe/H] in the…

Astrophysics · Physics 2009-10-31 Michael Feast , Patricia Whitelock

We model and analyse the secular evolution of stellar bars in spinning dark matter (DM) haloes with the cosmological spin lambda ~ 0 -- 0.09. Using high-resolution stellar and DM numerical simulations, we focus on angular momentum exchange…

Astrophysics of Galaxies · Physics 2018-02-21 Angela Collier , Isaac Shlosman , Clayton Heller

A rapidly rotating, axisymmetric star can be dynamically unstable to an m=2 "bar" mode that transforms the star from a disk shape to an elongated bar. The fate of such a bar-shaped star is uncertain. Some previous numerical studies indicate…

General Relativity and Quantum Cosmology · Physics 2010-11-19 David Brown

We present the BaLROG (Bars in Low Redshift Optical Galaxies) sample of 16 morphologically distinct barred spirals to characterise observationally the influence of bars on nearby galaxies. Each galaxy is a mosaic of several pointings…

We study the impact of bar-induced non-circular motions on the derivation of galactic rotation curves (RCs) using hydrodynamic simulations and observational data from the PHANGS-ALMA survey. We confirm that non-circular motions induced by a…

Astrophysics of Galaxies · Physics 2025-01-23 Jie Liu , Zhi Li , Juntai Shen

We describe a technique that uses radial color gradients in disk galaxies to detect the presence of bulk non-circular motion or elliptical orbits. In a disk galaxy with both a radial color gradient and non-circular motion, isochromes or…

Astrophysics · Physics 2016-08-15 A. C. Quillen , Solange V. Ramírez , Jay A. Frogel

Using $N$-body simulations we study the buckling instability in a galactic bar forming in a Milky Way-like galaxy. The galaxy is initially composed of an axisymmetric, exponential stellar disk embedded in a spherical dark matter halo. The…

Astrophysics of Galaxies · Physics 2019-09-04 Ewa L. Lokas

In the present article, we present a new gravitational galactic model, describing motion in elliptical as well as in disk galaxies, by suitably choosing the dynamical parameters. Moreover, a new dynamical parameter, the S(g) spectrum, is…

Astrophysics of Galaxies · Physics 2012-04-03 Euaggelos E. Zotos

We examine the dynamical effects on disk stars of a "long bar" in the Milky Way by inserting a triaxial rotating bar into an axisymmetric disk+bulge+dark halo potential and integrating 3-D orbits of 104 tracer stars over a period of 2 Gyr.…

Astrophysics · Physics 2010-09-23 Esko Gardner , Kimmo A. Innanen , Chris Flynn

As a planet transits the face of a star, it accelerates along the line-of-sight. The changing delay in the propagation of photons produces an apparent deceleration of the planet across the sky throughout the transit. This persistent…

Astrophysics · Physics 2009-11-10 Abraham Loeb

In this paper, we overlay a continuum of analytical relations which essentially serve to compute the arc-length described by a celestial body in an elliptic orbit within a stipulated time interval. The formalism is based upon a…

Computational Physics · Physics 2019-11-26 Aayush Jha , Ashim B. Karki

We show by numerical simulations that a purely stellar dynamical model composed of an exponential disc, a cuspy bulge, and an NFW halo with parameters relevant to the Milky Way Galaxy is subject to bar formation. Taking into account the…

Astrophysics of Galaxies · Physics 2016-08-17 Evgeny Polyachenko , Peter Berczik , Andreas Just

Using high resolution N-body simulations of stellar disks embedded in cosmologically motivated dark matter halos, we study the evolution of bars and the transfer of angular momentum between halos and bars. We find that dynamical friction…

Astrophysics · Physics 2009-11-07 Octavio Valenzuela , Anatoly Klypin