相关论文: How galaxies lose their angular momentum
We performed N-body/SPH simulations of merging gas rich disk-galaxies with a mass ratio of 3:1. A stellar disk and bulge component and a dark halo is realized with collisionless particles, the gas is simulated using SPH particles. In this…
The formation of compact objects like stars and black holes is strongly constrained by the requirement that nearly all of the initial angular momentum of the diffuse material from which they form must be removed or redistributed during the…
Observed galactic disks have specific angular momenta similar to expectations for typical dark matter halos in $\Lambda$CDM. Cosmological hydrodynamical simulations have recently reproduced this similarity in large galaxy samples by…
Disk galaxies at high redshift (z~2) are characterized by high fractions of cold gas, strong turbulence, and giant star-forming clumps. Major mergers of disk galaxies at high redshift should then generally involve such turbulent clumpy…
We study the detailed structure of galaxies at redshifts z > 2 using cosmological simulations with improved modeling of the interstellar medium and star formation. The simulations follow the formation and dissociation of molecular hydrogen,…
The role of dark matter halos in galaxy disk evolution is reviewed, in particular the stabilisation of disks through self-gravity reduction, or the bar development through angular momentum exchange. Triaxial dark halos tend to weaken bars.…
Within a fully cosmological hydrodynamical simulation, we form a galaxy which rotates at 140 km/s, and is characterised by two loose spiral arms and a bar, indicative of a Hubble Type SBc/d galaxy. We show that our simulated galaxy has no…
We present a detailed analysis of a disc galaxy forming in a high-resolution fully cosmological simulation to investigate the nature of the outer regions of discs and their relevance for the disc formation process. Specifically, we focus on…
We performed N-body/SPH simulations of merging gas-rich disk galaxies with mass ratios of 1:1 and 3:1. A stellar disk and bulge component and a dark halo was realized with collisionless particles, the gas was represented by SPH particles.…
It is likely that cold molecular clouds form at high redshift, before galaxies. Considering these cold clouds instead of hot homogeneous gas as the main baryonic component of proto-galactic halos may affect several issues during galaxy…
We use cosmological hydrodynamical simulations to show that a significant fraction of the gas in high redshift rare massive halos falls nearly radially to their very centre on extremely short timescales. This process results in the…
The surface brightness distribution in the majority of stellar galactic discs falls off exponentially. Often what lies beyond such a stellar disc is the neutral hydrogen gas whose distribution also follows a nearly exponential profile at…
We use FIRE simulations to study disk formation in z~0, Milky Way-mass galaxies, and conclude that a key ingredient for the formation of thin stellar disks is the ability for accreting gas to develop an aligned angular momentum distribution…
Two ways of possibly solving the angular momentum problem plaguing cold dark matter (CDM) ab initio simulations of disk galaxy formation are discussed: 1) Stellar feedback processes and 2) Warm dark matter (WDM) rather than CDM. In relation…
Several simple mergers between model galaxy clusters containing a mixture of gas and dark matter are examined, testing the coupling of the gas to the underlying collisionless material. The gas is shocked, irreversibly dissipating the energy…
We combine constraints on the galaxy-dark matter connection with structural and dynamical scaling relations to investigate the angular momentum content of disc galaxies. For haloes with masses in the interval 10^{11.3} < M_vir/M_sun <…
We discuss the role that numerical effects have in cosmological N-Body/SPH simulations of disk galaxy formation. We show that the resolution of current state-of-the-art calculations, about $10^5$ SPH and dark matter particles within the…
We use a state-of-the-art semi-analytic model to study the size and the specific angular momentum of galaxies. Our model includes a specific treatment for the angular momentum exchange between different galactic components. Disk scale radii…
During the growth of a cold dark matter halo, the direction of its spin can undergo rapid changes. These could disrupt or even destroy a stellar disc forming in the halo, possibly resulting in the generation of a bulge or spheroid. We…
This paper constructs an analytic framework for calculating the assembly of galactic disks from the collapse of gas within dark matter halos, with the goal of determining the surface density profiles. Gas parcels (baryons) fall through the…