Galaxies
You are currently browsing articles tagged Galaxies.
- Levine et al.
- http://arxiv.org/abs/0711.3478
- Simulation with high dynamic range (1E7) down to 0.1pc, i.e. to the accretion disk of a SMBH.
- Global instabilities make things quasi-stable locally due to turbulence.
- An exponential density profile for the gas in a disk arises naturally due to this.
Tags: Black Holes, Disk, Galaxies, Simulation
- Statistical model to predict/fit the star formation history of the universe. Hierarchical formation through merging seems to be favoured but not enough to exclude the monolithic scenario. Outflow models and dust are critical.
My impression is that the two priciple modes of galaxy formation seem to be subject to fashion among astronomers. While monolithic has been favoured in the early days of extragalacitc astronomy, the hierarchical formation was preferred until lately when it was realised that the former probably also plays a role.
Tags: Galaxies, high z, Star Formation, Statistics
- de Mello et al.
- http://arxiv.org/abs/0711.2685
- They found both old and young stars in the region between the two galaxies and conclude that the former were flung out of either of the two while the latter have formed in the tidal tail.
- Overall, there seems to be quite little going on there compared to other tidal tails (e.g. of mergers) where active star formation is often seen.
Tags: Galaxies, HST, Merger, Star Formation, Stellar Populations, UV
- Conference proceeding on how the MW is special in the sense that it forms little stars and therefore cannot have undergone a merger for a long time.
Tags: Galaxies, Kinematics, Merger, MilkyWay, TullyFisher
- Dijkstra et al.
- http://arxiv.org/abs/0711.2312
- numerical study of how LyA photons scatter and become polarizes
- difference for infall and outflow of gas
- polarimetric measurements proposed
Tags: Galaxies, high z, LyA, Polarization
- z=1 galaxies show more frequently “strange” kinematics than locally.
Tags: Galaxies, high z, Kinematics
- GCs can be “friendless”, meaning they have no neighbors with similar kinematics. In addition they look at various subsamples depending e.g. on metallicity and brightness.
Tags: Disk, Galaxies, GC, Kinematics
- similar to UM461? but bigger.
Tags: Galaxies, high z, Kinematics, LyBreak, Starburst
- They say they cannot “rule out” gas accretion, but I wonder where the dividing line goes between a gas-rich dwarf being eaten and infall of gas.
Tags: Dwarf, Elliptical, Galaxies, Merger, Simulation, UltraViolet
- Grillo et al.
- http://arxiv.org/abs/0711.0882
- Combining gravitational lensing and galaxy dynamics (velocity dispersion as a funciton of radius in ellipticals) as a new and independant (!) method of measuring the geometry of the universe.
- Way cool, if it ever gets on par in accuracy with the other methods.
Tags: Cosmology, Elliptical, Galaxies, Kinematics, Lensing
