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Related papers: Direct measurements of bar pattern speeds

200 papers

Hypothetical influences of variability of light velocity due to the parameters of the source of radiation, for the results of spectral measurements of stars to search for exoplanets are considered. Accounting accelerations of stars relative…

General Physics · Physics 2013-01-22 B. R. Mushailov , V. S. Teplitskaya

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…

We show how the continuity equation can be used to determine pattern speeds in the Milky Way Galaxy (MWG). This method, first discussed by Tremaine & Weinberg in the context of external galaxies, requires projected positions, $(l,b)$, and…

Astrophysics · Physics 2009-11-07 Victor P. Debattista , Ortwin Gerhard , Maartje N. Sevenster

With the steady increase of the sample size of observed microlenses towards the central regions of the Galaxy, the main source of the uncertainty in the lens mass will shift from the simple Poisson noise to the intrinsic non-uniqueness of…

Astrophysics · Physics 2009-10-30 HongSheng Zhao , P. Tim de Zeeuw

There is now clear evidence, from a variety of studies, that galactic bars contribute to and/or accelerate processes which quench galaxies. However, bars have a variety of strengths and pattern speeds, and previous work has suggested that…

Astrophysics of Galaxies · Physics 2026-04-22 Petra Mengistu , Karen L. Masters , Tobias Geron , R. J. Smethurst , Chris Lintott , B. D. Simmons

As the nearest large spiral galaxy, M31 provides a unique opportunity to learn about the structure and evolutionary history of this galaxy type in great detail. Among the many observing programs aimed at M31 are microlensing studies, which…

Astrophysics of Galaxies · Physics 2018-03-21 Michael Opitsch , Maximilian H. Fabricius , Roberto P. Saglia , Ralf Bender , Matias Blaña , Ortwin Gerhard

Current theories of dynamical friction on galactic bars are based either on linear perturbation theory, which is valid only in the fast limit where the bar changes its pattern speed rapidly, or on adiabatic theory, which is applicable only…

Astrophysics of Galaxies · Physics 2023-08-04 Rimpei Chiba

We have developed a new method for determining the corotation radii of density waves in disk galaxies, which makes use of the radial distribution of an azimuthal phase shift between the potential and density wave patterns. The approach…

Astrophysics · Physics 2008-11-26 Xiaolei Zhang , Ronald J. Buta

The strength and vertical distribution of atmospheric turbulence is a key factor determining the performance of optical and infrared telescopes, with and without adaptive optics. Yet, this remains challenging to measure. We describe a new…

Instrumentation and Methods for Astrophysics · Physics 2019-10-11 Paul Hickson , Bin Ma , Zhaohui Shang , Suijian Xue

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

The circular speed curve of the Milky Way provides a key constraint on its mass distribution, reflecting the axisymmetric component of the gravitational potential. This is especially critical in the inner Galaxy ($R \lesssim 4$ kpc), where…

Astrophysics of Galaxies · Physics 2025-07-18 Junichi Baba

Isolated barred galaxies evolve by redistributing their internal angular momentum, which is emitted mainly at the inner disc resonances and absorbed mainly at the resonances in the outer disc and the halo. This causes the bar to grow…

Astrophysics · Physics 2007-05-23 E. Athanassoula

Context. Kinematical data such as the mean velocities and velocity dispersions of stellar samples are useful tools to study galactic structure and evolution. However, observational data are often incomplete (e.g., lacking the radial…

Instrumentation and Methods for Astrophysics · Physics 2013-02-19 Toktam Aghajani , Lennart Lindegren

We study the mechanisms and evolutionary phases of bar formation in n-body simulations of a stellar disc and dark matter halo system using harmonic basis function expansion analysis to characterize the dynamical mechanisms in bar evolution.…

Astrophysics of Galaxies · Physics 2019-03-21 Michael S. Petersen , Martin D. Weinberg , Neal Katz

Most late-type stars in the solar neighborhood have velocities similar to the local standard of rest (LSR), but there is a clearly separated secondary component corresponding to a slower rotation and a mean outward motion. Detailed…

Astrophysics · Physics 2009-10-31 Walter Dehnen

We present a new high-resolution neutral atomic hydrogen (HI) survey of ring galaxies using the Australia Telescope Compact Array (ATCA). We target a sample of 24 ring galaxies from the Buta (1995) Southern Ring Galaxy Survey Catalogue in…

Stars are not smooth. Their photosphere is covered by a granulation pattern associated with the heat transport by convection. The convection-related surface structures have different size, depth, and temporal variations with respect to the…

Solar and Stellar Astrophysics · Physics 2016-09-28 A. Chiavassa , L. Bigot

A multi-faceted approach is described to constrain the importance of bar-driven evolution in disk galaxies, particularly bulge formation. N-body simulations are used to construct stellar kinematic bar diagnostics for edge-on systems and to…

Astrophysics · Physics 2016-01-27 M. Bureau , E. Athanassoula , A. Chung , G. Aronica

We run N-body smoothed particle hydrodynamics (SPH) simulations of a Milky Way sized galaxy. The code takes into account hydrodynamics, self-gravity, star formation, supernova and stellar wind feedback, radiative cooling and metal…

Astrophysics of Galaxies · Physics 2015-06-04 Robert J. J. Grand , Daisuke Kawata , Mark Cropper

Using hydrodynamic simulations, we investigate the physical properties of gaseous substructures in barred galaxies and their relationships with the bar strength. The gaseous medium is assumed to be isothermal and unmagnetized. The bar…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Woong-Tae Kim , Woo-Young Seo , Yonghwi Kim
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