Related papers: Why (inner) bars are important but not sufficient
Within the NUclei of GAlaxies project we have obtained IRAM PdBI and 30m 12CO(1-0) and 12CO(2-1) observations of the spiral galaxy NGC 6951. Previous work shows that there is indirect evidence of gas inflow from 3 kpc down to small radii: a…
We investigate the role of galactic bars in fuelling and triggering Active Galactic Nucleus (AGN) in disc galaxies up to $z\sim 0.8$. We utilise a Deep Learning model, fine-tuned on Galaxy Zoo volunteer classifications, to identify…
We review several aspects of clusters of galaxies and their application to cosmology. We present first results of numerical simulations of the dynamics of the intra-cluster gas and of different interaction processes between cluster galaxies…
Although it is clear that the circumnuclear regions of galaxies are intimately related to their host galaxies, most directly through their bars, it remains unclear what exactly initiates and fuels nuclear stellar (starburst) and non-stellar…
Recent progress in the understanding of the role of bars and gravitational instabilities in galaxy disks is reviewed. It has been proposed that bars can produce mass transfer towards the center, and progressively metamorphose late-type…
A specific theoretical framework is important for designing and conducting an experiment, and for interpretation of its results. The field of gravitational physics is expanding, and more clarity is needed. It appears that some popular…
Asymmetries in galactic potentials, either self-induced, or caused by a passing companion, play an important role in global gas dynamics in galaxies. In particular, they are able to trigger gas inflow, which in turn feeds nuclear activity.…
I present a brief review of what is known about double-barred galaxies, where a small ("inner") bar is nested inside a larger ("outer") bar; the review is focused primarily on their demographics and photometric properties. Roughly 20% of…
Stellar bars are elongated structures in disk galaxies that can torque and funnel gas inward, influencing galaxy evolution. While strong bars are known to induce rapid inflow, the impact of weaker bars remains less certain. We collected…
1) Background: the budget of non-thermal energy in galaxy clusters is not well constrained, owing to the observational and theoretical difficulties in studying these diluted plasmas on large scales. 2) Method: we use recent cosmological…
Bar structures are present in about half of local disk galaxies and play pivotal roles in secular galaxy evolution. Bars impose a non-axisymmetric perturbation to the rotating disk and transport gas inward to feed central starburst and,…
A substantial fraction of disk galaxies is double-barred. We analyze the dynamical stability of such nested bar systems by means of Liapunov exponents,by fixing a generic model and varying the inner (secondary) bar mass. We show that there…
Double-barred galaxies are common in the local Universe, with approximately one third of barred spirals hosting an smaller, inner bar. Nested bars have been proposed as a mechanism for transporting gas to the very central regions of the…
We report here results of high-resolution hydrodynamical simulations of gas flows in barred galaxies, with a focus on gas dynamics in the central kiloparsec. In a single bar with an Inner Lindblad Resonance, we find either near-circular…
The problem of determining the pattern of gas motions in the central cases -- noncircular motions in the triaxial bar potential and motions in circular orbits but with orientation parameters different from those of the main disk -- are…
I summarize a series of studies where the underlying theme is to exploit non-axisymmetry disk structures such as bars and spiral arms. By measuring the strength of gravitational forces from these structures we can measure the mass in them.…
The high-energy universe has revealed that energetic particles are ubiquitous in the cosmos and play a vital role in the cultivation of cosmic environments on all scales. Though they play a key role in cultivating the cosmological…
In this review, I discuss just three aspects of the stability and evolution of galactic discs. (1) I first review our understanding of the bar instability and how it can be controlled. Disc galaxies in which the orbital speed does not…
Galactic disks can form in asymmetric potentials of the assembling dark matter (DM) halos, giving rise to the first generation of gas-rich bars. Properties of these bars differ from canonical bars analyzed so far. Moreover, rapid disk…
Although at least one quarter of early-type barred galaxies host secondary stellar bars embedded in their large-scale primary counterparts, the dynamics of such double barred galaxies are still not well understood. Recently we reported…