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Related papers: Stellar Dynamics and the 3D Structure of Bars

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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

We study the properties of two bars formed in fully cosmological hydrodynamical simulations of the formation of Milky Way-mass galaxies. In one case, the bar formed in a system with disc, bulge and halo components and is relatively strong…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Cecilia Scannapieco , Evangelia Athanassoula

We investigate the connection between the vertical structure of stellar discs and the formation of bars using high-resolution simulations of galaxies in isolation and in the cosmological context. In particular, we simulate a suite of…

Astrophysics of Galaxies · Physics 2019-02-27 Jacob S. Bauer , Lawrence M. Widrow

Disk galaxies evolve over time through processes that may rearrange both the radial mass profile and the metallicity distribution within the disk. This review of such slow changes is largely, though not entirely, restricted to…

Astrophysics of Galaxies · Physics 2015-06-17 J. A. Sellwood

After a recall of fundamental concepts used in galactic dynamics, we review observational facts as well as results of orbit theory and numerical simulations which suggest long-term evolution of galaxies. Dynamical interactions between…

Astrophysics · Physics 2007-05-23 Louis Martinet

Secular evolution and fueling is driven by bars in spiral galaxies, and the related dynamical processes are reviewed. It is shown that gravity torques dominate over viscous torques, and produce gas infall to the center. In this infall, the…

Astrophysics · Physics 2009-11-10 Francoise Combes

Many strong simulated galactic bars experience buckling instability, which manifests itself as a vertical distortion out of the disk plane, and later dissipates. Using a simulation of an isolated Milky Way-like galaxy, I demonstrate that…

Astrophysics of Galaxies · Physics 2025-07-09 Ewa L. Lokas

Secular evolution gradually shapes galaxies by internal processes, in contrast to early cosmological evolution which is more rapid. An important driver of secular evolution is the flow of gas from the disk into the central regions, often…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Johan H. Knapen

Young stellar bars in disk galaxies experience a vertical buckling instability which terminates their growth and thickens them, resulting in a characteristic peanut/boxy shape when viewed edge on. Using N-body simulations of galactic disks…

Astrophysics · Physics 2009-11-10 Inma Martinez-Valpuesta , Isaac Shlosman

The evolution of star clusters is determined by several internal and external processes. Here we focus on two dominant internal effects, namely energy exchange between stars through close encounters (two-body relaxation) and mass-loss of…

Astrophysics of Galaxies · Physics 2011-06-24 Mark Gieles

In this and in a previous paper (Romero-Gomez et al. 2006) we propose a theory to explain the formation of both spirals and rings in barred galaxies using a common dynamical framework. It is based on the orbital motion driven by the…

Astrophysics · Physics 2009-11-13 M. Romero-Gomez , E. Athanassoula , J. J. Masdemont , C. Garcia-Gomez

By means of self-consistent numerical simulations we investigated the dynamical impact of classical bulges on the growth of the secondary buckling of a bar. Overall we considered 14 models with different disc and bulge parameters. We…

Astrophysics of Galaxies · Physics 2019-02-25 Anton A. Smirnov , Natalia Ya. Sotnikova

The regular or chaotic dynamics of an analytical realistic three dimensional model composed of a spherically symmetric central nucleus, a bar and a flat disk is investigated. For describing the properties of the bar we introduce a new…

Astrophysics of Galaxies · Physics 2015-11-18 Christof Jung , Euaggelos E. Zotos

The dynamical evolution of stellar clusters is driven to a large extent by their environment. Several studies so far have considered the effect of tidal fields and their variations, such as, e.g., from giant molecular clouds, galactic…

Astrophysics of Galaxies · Physics 2015-05-30 I. Berentzen , E. Athanassoula

We investigate the orbital structure in a class of 3D models of barred galaxies. We consider different values of the pattern speed, of the strength of the bar and of the parameters of the central bulge of the galactic model. The morphology…

Astrophysics · Physics 2009-11-07 Ch. Skokos , P. A. Patsis , E. Athanassoula

The life of disk galaxies is likely punctuated with the birth (spontaneous or induced), the aging (quick or slow), and the death (sudden or progressive) of bars. These events are responsible for various major changes of the galaxy which…

Astrophysics · Physics 2007-05-23 D. Friedli

We characterize empirically the radial diffusion of stars in the plane of a typical barred disk galaxy by calculating the local spatial diffusion coefficient and diffusion time-scale for bulge-disk-halo N-body self-consistent systems which…

Astrophysics of Galaxies · Physics 2015-05-30 Maura Brunetti , Cristina Chiappini , Daniel Pfenniger

We discuss the evolution of a disc galaxy due to the formation of a bar and, subsequently, a peanut. After the formation stage there is still considerable evolution, albeit slower. In purely stellar cases the pattern speed of the bar…

Astrophysics · Physics 2009-11-07 E. Athanassoula

Strong galactic bars produced in simulations tend to undergo a period of buckling instability that weakens and thickens them and forms a boxy/peanut structure in their central parts. This theoretical prediction has been confirmed by…

Astrophysics of Galaxies · Physics 2019-04-03 Ewa L. Lokas

Inner regions of barred disk galaxies often include asymmetrical, small-scale central features, some of which are best described as secondary bars. Because orbital timescales in the galaxy center are short, secondary bars are likely to be…

Astrophysics · Physics 2007-05-23 Witold Maciejewski , Linda S. Sparke