相关论文: Lopsided spiral galaxies: evidence for gas accreti…
We describe the kinematics of circumgalactic gas near the galactic plane, combining new measurements of galaxy rotation curves and spectroscopy of background quasars. The sightlines pass within 19--93 kpc of the target galaxy and generally…
While all models for the evolution of galaxies require the accretion of gas to sustain their growth via on-going star formation, it has proven difficult to directly detect this inflowing material. In this paper we use data of nearby…
The formation of thick stellar disks in spiral galaxies is studied. Simulations of gas-rich young galaxies show formation of internal clumps by gravitational instabilities, clump coalescence into a bulge, and disk thickening by strong…
Evidence for the accretion of material in spiral galaxies has grown over the past years and clear signatures can be found in HI observations of galaxies. We describe here new detailed and sensitive HI synthesis observations of a few nearby…
Disk galaxies are in hydrostatic equilibrium along their vertical axis. The pressure allowing for this configuration consists of thermal, turbulent, magnetic and cosmic ray components. For the Milky Way(MW) the thermal pressure contributes…
Studies of the HI in galaxies have clearly shown that subtle details of the HI distribution and kinematics often harbour key information for understanding the structure and evolution of galaxies. Evidence for the accretion of material has…
We examine in detail the dynamical structure of an elliptical galaxy simulated in the Lambda CDM scenario. The morphology of the galaxy evolves dramatically over time in response to the mode and timing of mass accretion; smooth deposition…
Using the deepest and the most complete set of observations of distant galaxies, we investigate how extended disks could have formed. Observations include spatially-resolved kinematics, detailed morphologies and photometry from UV to…
We use cosmological SPH simulations to study the kinematic signatures of cool gas accretion onto a pair of well-resolved galaxy halos. Cold-flow streams and gas-rich mergers produce a circum-galactic component of cool gas that generally…
Galaxies in clusters are gas-deficient and a number of possible explanations for this observation have been advanced, including galaxy-cluster tidal interactions, galaxy harassment, and ISM-ICM gas stripping. In this paper, we use a…
Satellites are not randomly distributed around their central galaxies but show polar and planar structures. In this paper, we investigate the axis-asymmetry or lopsidedness of satellite galaxy distributions around isolated galaxies in a…
Axisymmetric disks of eccentric orbits in near-Keplerian potentials are unstable to an out-of-plane buckling. Recently, Zderic et al. (2020) showed that an idealized disk saturates to a lopsided mode. Here we show that this apsidal…
High-resolution numerical simulations of galaxy mergers are analysed. The global structure and isophotal shapes of the merger remnants are in good agreement with the observations. Whereas equal-mass mergers lead to anisotropic, boxy…
To probe the progenitors of the numerous massive spirals requires to dissect distant galaxy properties through spatially-resolved kinematics, detailed morphologies and photometry from UV to mid-IR. So far IMAGES is the only representative…
Obscured or narrow-line active galaxies offer an unobstructed view of the quasar environment in the presence of a luminous and vigorously accreting black hole. We exploit the large new sample of optically selected luminous narrow-line…
We consider seven distant galaxies with clearly evident spiral structure from HST images. Three of these were chosen from Vogt et al. (1996) (VFP) and have measured rotational velocities. Five were chosen from the Medium Deep Survey and are…
While the formation of stellar clumps in distant galaxies is usually attributed to gravitational violent disk instabilities, we show here that major mergers also represent a competitive mechanism to form bright clumps. Using ~0.1''…
About two-thirds of present-day, large galaxies are spirals such as the Milky Way or Andromeda, but the way their thin rotating disks formed remains uncertain. Observations have revealed that half of their progenitors, six billion years…
The driving of turbulence in galaxies is deeply connected with the physics of feedback, star formation, outflows, accretion, and radial transport in disks. The velocity dispersion of gas in galaxies therefore offers a promising…
We investigate detailed kinematical properties of simulated collisionless merger remnants of disk galaxies with mass ratios of 1:1 and 3:1. The simulations were performed by direct summation using the new special hardware device GRAPE-5. In…