Related papers: Secular evolution in galaxies
Bulges are of different types, morphologies and kinematics, from pseudo-bulges, close to disk properties (Sersic index, rotation fraction, flatenning), to classical de Vaucouleurs bulges, close to elliptical galaxies. Secular evolution and…
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…
Galaxy evolution is in transition from an early universe dominated by hierarchical clustering to a future dominated by secular processes. These result from interactions involving collective phenomena such as bars, oval disks, spiral…
Galaxy disks evolve through angular momentum transfers between sub-components, like gas, stars, or dark matter halos, through non axi-symmetric instabilities. The speed of this evolution is boosted in presence of a large fraction of cold…
Self-gravitating systems evolve toward the most tightly bound configuration that is reachable via available evolution processes. The inner parts shrink and the outer parts expand, provided that some physical process transports energy or…
We use high resolution collisionless $N$-body simulations to study the secular evolution of disk galaxies and in particular the final properties of disks that suffer a bar and perhaps a bar-buckling instability. Although we find that bars…
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…
Stellar bars are important internal drivers of secular evolution in disk galaxies. Using a sample of nearby spiral galaxies with weak and strong bars, we explore the relationships between the star formation feature and stellar bars in…
We review internal processes of secular evolution in galaxy disks, concentrating on the buildup of dense central features that look like classical, merger-built bulges but that were made slowly out of disk gas. We call these pseudobulges.…
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…
Through vertical resonances, bars can produce pseudo-bulges, within secular evolution. Bulges and pseudo-bulges have doubled their mass since z=1. The frequency of bulge-less galaxies at z=0 is difficult to explain, especially since clumpy…
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…
Dynamical evolution of spiral galaxies is strongly dependent on non-axisymmetric patterns that develop from gravitational instabilities, either spontaneously or externally triggered. Some evolutionary sequences are described through which a…
We review internal secular evolution in galaxy disks -- the fundamental process by which isolated disks evolve. We concentrate on the buildup of dense central features that look like classical, merger-built bulges but that were made slowly…
It is now a well established fact that galaxies undergo significant morphological transformation during their lifetimes, manifesting as an evolution along the Hubble sequence from the late to the early Hubble types. The physical processes…
The existence of a classical bulge in disk galaxies holds important clue to the assembly history of galaxies. Finding observational evidence of very low mass classical bulges particularly in barred galaxies including our Milky Way, is a…
Classical bulges and stellar bars are common features in disk galaxies and serve as key tracers of galactic evolution. Angular momentum exchange at bar resonances drives secular morphological changes throughout the disk, including bar…
The evolution of galaxies results from a combination of internal and external processes. The star formation is an internal process transforming cold and dense cores of molecular clouds to stars. It may be triggered internally by expanding…
Galaxy morphology has many structures that are suggestive of various processes or stages of secular evolution. Internal perturbations such as bars can drive secular evolution through gravity torques that move gas into the central regions…
Except in the most extreme cases of nuclear activity, either starbursts or AGN, it is difficult to find observationnally a close link between the dynamics and the activity. Theoretically however, the necessary step to fuel the gas to the…