Related papers: The role of bars
Spiral patterns are important agents of galaxy evolution. In this review, I describe how the redistribution of angular momentum by recurrent transient spiral patterns causes the random speeds of stars to rise over time, metallicity…
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…
Bars drive the dynamical evolution of disk galaxies by redistributing mass and angular momentum, and they are ubiquitous in present-day spirals. Early studies of the Hubble Deep Field reported a dramatic decline in the rest-frame optical…
To investigate the role of bars in the chemical evolution of isolated disc galaxies, we performed a series of 39 gas dynamical simulations of isolated barred and unbarred galaxies with various masses, initial gas fractions, and AGN feedback…
The presence of stars on retrograde orbits in disc galaxies is usually attributed to accretion events, both via direct accretion, as well as through the heating of the disc stars. Recent studies have shown that retrograde orbits can also be…
The evolution of galaxies is driven strongly by dynamical processes including internal instabilities, tidal interactions and mergers. The cluster environment is a useful laboratory for studying these effects. I present recent results on…
Identifying the structure of our Galaxy has always been fraught with difficulties, and while modern surveys continue to make progress building a map of the Milky Way, there is still much to understand. The arm and bar features are important…
AIMS. The non-conservative gravitational potential of barred galaxies, or of any other non-axisymmetric structure, produces a loss of energy in infalling particles of the intergalactic medium into the galaxy, which are trapped in its…
In current $\Lambda$CDM galaxy formation scenarios, at least three physical phenomena could contribute to the mass assembly: monolithic collapse, hierarchical mergers and more quiescent external gas accretion, with secular evolution. The…
How does the gas get in nuclear regions to fuel black holes? How efficient is the feedback? The different processes to cause rapid gas inflow (or outflow) in galaxy centers are reviewed. Non axisymmetries can be created or maintained by…
An overwhelming majority of galactic spiral arms trail with respect to the rotation of the galaxy, though a small sample of leading spiral arms has been observed. The formation of these leading spirals is not well understood. Here we show,…
The evolution of a stellar bar transforms not only the galactic disk, but also the host dark matter halo. We present high resolution, fully self-consistent N-body simulations that clearly demonstrate that dark matter halo central density…
We study two dimensional Fabry-Perot interferometric observations of the nearby face-on late-type spiral galaxy, NGC 628. We investigate the role of the individual HII regions together with the large-scale gravitational mechanisms which…
This chapter reviews theoretical work on the stellar dynamics of galaxy disks. All the known collective global instabilities are identified, and their mechanisms described in terms of local wave mechanics. A detailed discussion of warps and…
Double-barred galaxies account for almost one third of all barred galaxies, suggesting that secondary stellar bars, which are embedded in large-scale primary bars, are long-lived structures. However, up to now it has been hard to…
Our Galaxy is a complex machine in which several processes operate simultaneously: metal-poor gas is accreted, is chemically enriched by dying stars, and then drifts inwards, surrendering its angular momentum to stars; new stars are formed…
Of the mechanisms proposed to bring gaseous fuel into the central starburst regions of a galaxy, non-axisymmetries in the gravitational potential set up by interactions or by bars are among the most promising. Nevertheless, direct…
I review the arguments for the importance of halo structure in driving galaxy evolution and coupling a galaxy to its environment. We begin with a general discussion of the key dynamics and examples of structure dominated by modes. We find…
We present the first attempt to analyse the growth of the bar instability in stellar-gaseous disks evolving in a fully consistent cosmological scenario. We explored the role of the cosmology on pure stellar disks with different mass…
We investigate the formation and evolution of nested bar systems in disk galaxies in a cosmological setting by following the development of an isolated dark matter (DM) and baryon density perturbation. The disks form within the assembling…