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Related papers: New Constraints on the Galactic Bar

200 papers

A strong bar rotating within a massive halo should lose angular momentum to the halo through dynamical friction, as predicted by Weinberg. We have conducted fully self-consistent, numerical simulations of barred galaxy models with a live…

Astrophysics · Physics 2015-06-24 J. A. Sellwood , Victor P. Debattista

OB associations, as an intermediate stage between Galactic clusters and field stars, play an important role in understanding the star formation process, early stellar evolution, and Galactic evolution. In this work, we construct a large…

Astrophysics of Galaxies · Physics 2025-08-12 Zhicun Liu , Xiao-Long Wang , Wenyuan Cui , Jianrong Shi , Chao Liu , Xiang-Xiang Xue , Min Fang , Yang Huang , Guozhen Hu , Gang Zhao

We have done a detailed study on the structural and kinematical properties of lenticular and early- and late-type spiral galaxies with bars, aiming to explore the formation and evolution processes of stellar bars in galaxies, and their…

Astrophysics · Physics 2009-11-10 Dimitri Alexei Gadotti

The oxygen (O/H) and N/O abundance ratios along the bar of 16 barred spiral starburst galaxies are determined using long-slit spectroscopy. The abundance gradients and the spatial distribution of the ionized gas along the bar are used to…

Astrophysics · Physics 2007-05-23 S. Considere , R. Coziol , T. Contini , E. Davoust

We present the first study of bars in the local Universe, based on the Sloan Digitized Sky Survey (SDSS). The large sample of ~5000 local galaxies provides the largest study to date of local bars and minimizes the effect of cosmic variance.…

Astrophysics · Physics 2009-11-11 Fabio D. Barazza , Shardha Jogee , Irina Marinova

We determine the values of parameters of an N-body model for the Galaxy developed by Fux via comparison with an unbiased, homogeneous sample of OH/IR stars. Via Monte-Carlo simulation, we find the plausibilities of the best-fitting models,…

Astrophysics · Physics 2009-10-31 M. Sevenster , P. Saha , D. Valls-Gabaud , R. Fux

An analysis of the kinematics of open star clusters (OSCs) using their characteristics from the new Hunt and Reffert catalog was conducted. Based on 4003 OSCs younger than 200 million years, the following values for the angular velocity of…

Astrophysics of Galaxies · Physics 2026-05-05 Vadim V. Bobylev , Anisa T. Bajkova

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

We investigate the evolution of two bars formed in fully self-consistent hydrodynamic simulations of the formation of Milky Way-mass galaxies. One galaxy shows higher central mass concentration and has a longer and stronger bar than the…

Astrophysics of Galaxies · Physics 2015-04-29 Takashi Okamoto , Mari Isoe , Asao Habe

As part of on an extensive data mining effort, we have compiled a database of 162 Galactic rotation speed measurements at $R_0$ (the solar Galactocentric distance), $\Theta_0$. Published between 1927 and 2017 June, this represents the most…

Astrophysics of Galaxies · Physics 2017-10-11 Richard de Grijs , Giuseppe Bono

Studies of the dynamics of globular clusters assume different values of bar parameters (mass, velocity, size) and analyse the results of orbit classifications over the range of the chosen values. It is also a usual thing that a spherical…

Astrophysics of Galaxies · Physics 2024-01-05 Anton A. Smirnov , Anisa T. Bajkova , Vadim V. Bobylev

Spatial velocities of all currently known 28 masers having trigonometric parallaxes, proper motion and line-of-site velocities are reanalyzed using Bottlinger's equations. These masers are associated with 25 active star-forming regions and…

Astrophysics of Galaxies · Physics 2015-05-19 Vadim Bobylev , Anisa Bajkova

When bars form within galaxy formation simulations in the standard cosmological context, dynamical friction with dark matter (DM) causes them to rotate rather slowly. However, almost all observed galactic bars are fast in terms of the ratio…

Astrophysics of Galaxies · Physics 2021-03-30 Mahmood Roshan , Indranil Banik , Neda Ghafourian , Ingo Thies , Benoit Famaey , Elena Asencio , Pavel Kroupa

Galactic bars, made up of elongated and aligned stellar orbits, can lose angular momentum via resonant torques with dark matter particles in the halo and slow down. Here we show that if a stellar bar is decelerated to zero rotation speed,…

Astrophysics of Galaxies · Physics 2023-05-12 Angela Collier , Ann-Marie Madigan

The present work is devoted to study the dynamical evolution of the galaxies in scalar-GaussBonnet gravity in relationship with the MOND paradigm. This study is useful for giving meaning to the presence of a new gravitational constant. The…

General Relativity and Quantum Cosmology · Physics 2022-01-19 M. Bousder

Stellar bars and spiral arms co-exist and co-evolve in most disc galaxies in the local Universe. However, the physical nature of this interaction remains a matter of debate. In this work, we present a set of numerical simulations based on…

Astrophysics of Galaxies · Physics 2021-02-17 L. Garma-Oehmichen , L. Martinez-Medina , H. Hernández-Toledo , I. Puerari

The geometry of the LMC bar is studied using the de-reddened mean magnitudes of the red clump stars ($I_0$) from the OGLE II catalogue. The value of $I_0$ is found to vary in the east-west direction such that both the east and the west ends…

Astrophysics · Physics 2007-05-23 Annapurni Subramaniam

We propose a method for measuring the cosmological density parameter $\Omega$ from the statistics of the divergence field, $\theta \equiv H^{-1} \div v$, the divergence of peculiar velocity, expressed in units of the Hubble constant, $H…

Astrophysics · Physics 2015-06-24 F. Bernardeau , R. Juszkiewicz , A. Dekel , F. R. bouchet

We built three models for the gravitational field of the Galactic bar. These models are an inhomogeneous ellipsoid, an inhomogeneous prolate spheroid, and a superposition of four inhomogeneous ellipsoids. Among the three models, the…

Astrophysics · Physics 2009-11-10 Barbara Pichardo , Marco Martos , Edmundo Moreno