Evolution of stellar-gaseous disks in cosmological haloes

Abstract

We explore the growth and the evolution of the bar instability in stellar-gaseous disks embedded in a suitable dark matter halo evolving in a fully consistent cosmological framework. The aim of this paper is to point out the impact of different gas fractions on the bar formation, inside disks of different disk-to-halo mass ratio, and the role of the cosmological framework. We perform cosmological simulations with the same disk-to-halo mass ratios as in a previous work where the gas was not taken into account. We compare results of the new simulations with the previous ones to investigate the effect of the gas by analysing the morphology of the stellar and gaseous components, the stellar bar strength and the behaviour of its pattern speed. In our cosmological simulations, inside dark-matter dominated disks, a stellar bar, lasting 10 Gyr, is still living at z=0 even if the gaseous fraction exceeds half of the disk mass. However, in the most massive disks we find a threshold value (0.2) of the gas fraction able to destroy the bar. The stellar bar strength is enhanced by the gas and in the more massive disks higher gas fractions increase the bar pattern speed.

arXiv comment13 pages, 14 figures (2 in low-res), A&A in press

References in corpus (22)

• A Universal Density Profile from Hierarchical Clustering
• The Structure of Cold Dark Matter Halos
• The cosmological simulation code GADGET-2
• Concentrations of Dark Halos from their Assembly Histories
• Star Formation and Feedback in Smoothed Particle Hydrodynamic Simulations--I. Isolated Galaxies
• Forming Disk Galaxies in Lambda CDM Simulations
• Morphology, photometry and kinematics of N-body bars. I Three models with different halo central concentrations
• Resolving the Structure of Cold Dark Matter Halos II
• Simulations of Galaxy Formation in a Lambda CDM Universe I: Dynamical and Photometric Properties of a Simulated Disk Galaxy
• Dark Halo and Disk Galaxy Scaling Laws in Hierarchical Universes
• The Formation of a Realistic Disk Galaxy in Lambda Dominated Cosmologies
• Disk Galaxy Formation in a LambdaCDM Universe
• The Destruction of Bars by Central Mass Concentrations
• The life-time of galactic bars: central mass concentrations and gravity torques
• A Dust-Penetrated Classification Scheme for Bars as Inferred from their Gravitational Force Fields
• Gas-driven evolution of stellar orbits in barred galaxies
• Modeling Angular-Momentum History in Dark-Matter Halos
• Where are the ``Missing'' Galactic Baryons?
• Simulations of Normal Spiral Galaxies
• The length of stellar bars in SB galaxies and N-body simulations
• Bar instability in cosmological halos
• Numerical Simulations of Interacting Gas-Rich Barred Galaxies

Cited by in corpus (9)

• The Galaxy and its stellar halo: insights on their formation from a hybrid cosmological approach
• Dark Matter Halos and Evolution of Bars in Disk Galaxies: Varying Gas Fraction and Gas Spatial Resolution
• Quantifying the role of bars in the build-up of central mass concentrations in disk galaxies
• Pseudobulge Formation as a Dynamical Rather than a Secular Process
• Stellar Disks in Aquarius Dark Matter Haloes
• When Should We Treat Galaxies as Isolated?
• Star formation and bar instability in cosmological haloes
• Evolution and instabilities of disks harboring super massive black holes
• Anisotropic Models of Dark Halos