Related papers: Dynamics of the Bar at the Galactic Centre
I present here a review on the high energy phenomena occurring in the Galactic Center region, and report in particular on the results obtained from recent X-ray and gamma-ray observations.
I review some of the work on bars which is closely linked to the bar/bulge system in our Galaxy. Several independent studies, using totally independent methods, come to the same results about the 3D structure of a bar, i.e., that a bar is…
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…
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…
Recent data from the VVV survey have strengthened evidence for a structural change in the Galactic bulge inwards of |l|<=4 deg. Here we show with an N-body barred galaxy simulation that a boxy bulge formed through the bar and buckling…
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…
We review general observational properties of bars in galaxies, and relations between bars, their dynamics, and (circum)nuclear activity. We consider new measurements of bar fractions and of the distribution of bars with host type, bar…
New constraints on the Milky Way's bar parameters are derived from the gaseous spiral structure within the Galactic bar, and in particular from the identification of the dustlanes leading the bar major axis.
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…
We make use of recent estimates for the parameters of the Milky Way's halo globular clusters and study the influence of the galactic bar on the dynamics of these clusters by computing their orbits. We use both an axisymmetric and…
One of the main properties of galactic bars is their rotation (or pattern) speed, which is driven by both internal galactic properties, as well as external interactions. To assess the influence of these internal and external drivers on bar…
Observational data indicate that the Milky Way is a barred spiral galaxy. Computation facilities and availability of data from Galactic surveys stimulate the appearance of models of the Galactic structure. More efforts to build dynamical…
We describe fully self-consistent N-body experiments of barred galaxies with massive halos. A rotating bar is braked through dynamical friction with the halo, which occurs on a short time scale when the central density of the halo is high.…
It has been suggested that a resonance between a rotating bar and stars in the solar neighbourhood can produce the so called 'Hercules stream'. Recently, a second bar may have been identified in the Galactic centre, the so called 'long…
We use fully self-consistent N-body simulations of barred galaxies to show that dynamical friction from a dense dark matter halo dramatically slows the rotation rate of bars. Our result supports previous theoretical predictions for a bar…
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…
I present some new results, from simulations and observations, of the constraints bar pattern speeds place on the dark matter content of disk galaxies.
We review the observational evidences concerning the three-dimensional structure of the Galactic bulge. Although the inner few kpc of our Galaxy are normally referred to as {\it the bulge}, all the observations demonstrate that this region…
New observations in favour of a significant role of secular evolution are reviewed: central star formation boosted in pseudo-bulge barred galaxies, relations between bulge and disk, evidence for rejuvenated bulges. Numerical simulations…
Density waves in the central kpc of galaxies, taking the form of spirals, bars and/or lopsided density distributions, are potential actors of the redistribution of angular momentum. They may thus play an important role in the overall…