Internal kinematics of galaxies in clusters. I - Velocity dispersions for elliptical galaxies in Coma and Virgo

1984 ◽  
Vol 281 ◽  
pp. 512 ◽  
Author(s):  
A. Dressler
Keyword(s):  
Elliptical Galaxies ◽  
Velocity Dispersions

scholarly journals The Evolution of Galaxies in Clusters

2003 ◽  
Vol 208 ◽  
pp. 237-244 ◽  
Author(s):  
John Dubinski ◽  
Dan Koranyi ◽  
Margaret Geller
Keyword(s):  
Spiral Galaxies ◽  
Dynamical Evolution ◽  
Elliptical Galaxies ◽  
Diffuse Light ◽  
Fundamental Plane ◽  
Numerical Investigations ◽  
Evolution Of Galaxies ◽  
Density Relationship ◽  
Velocity Dispersions

We report on recent numerical investigations of the dynamical evolution of galaxies in clusters. Simulations of spiral galaxies falling into forming clusters show the development of the morphology-density relationship and the formation of regular and giant elliptical galaxies. The regular elliptical merger remnants end up in a fundamental plane very similar to the observed relation. The giant ellipticals have much in common with their real counterparts but their central velocity dispersions are too high. We also quantify the amount and distribution of diffuse light in clusters.

scholarly journals The outer haloes of massive, elliptical galaxies

2009 ◽  
Vol 5 (H15) ◽  
pp. 92-92
Author(s):  
Payel Das ◽  
Ortwin Gerhard ◽  
Flavio de Lorenzi ◽  
Emily McNeil ◽  
Eugene Churazov ◽  
...  
Keyword(s):  
Dark Matter ◽  
Parametric Method ◽  
Elliptical Galaxies ◽  
Matter Content ◽  
Likelihood Method ◽  
Orbital Structure ◽  
Dynamical Models ◽  
X Ray ◽  
Mass Distributions ◽  
Velocity Dispersions

The outer haloes of massive elliptical galaxies are dark-matter dominated regions where stellar orbits have longer dynamical timescales than the central regions and therefore better preserve their formation history. Dynamical models out to large radii suffer from a degeneracy between mass and orbital structure, as the outer kinematics are unable to resolve higher moments of the line-of-sight velocity distribution. We mitigate this degeneracy for a sample of quiescent, massive, nearby ellipticals by determining their mass distributions independently using a non-parametric method on X-ray observations of the surrounding hot interstellar medium. We then create dynamical models using photometric and kinematic constraints consisting of integral-eld, long-slit and planetary nebulae (PNe) data extending to ~50 kpc. The rst two galaxies of our sample, NGC 5846 and NGC 1399, were found to have very shallow pro jected light distributions with a power law index of ~1.5 and a dark matter content of 70–80% at 50 kpc. Spherical Jeans models of the data show that, in the outer haloes of both galaxies, the pro jected velocity dispersions are almost inde- pendent of the anisotropy and that the PNe prefer the lower end of the range of mass distributions consistent with the X-ray data. Using the N-body code NMAGIC, we cre- ated axisymmetric models of NGC 5846 using the individual PNe radial velocities in a likelihood method and found them to be more constraining than the binned velocity dispersions. Characterising the orbital structure in terms of spherically averaged proles of the velocity dispersions we nd σψ > σr > σθ.

scholarly journals The effect of environment on the fundamental plane of elliptical galaxies

2014 ◽  
Vol 11 (S308) ◽  
pp. 471-472
Author(s):  
R. Kipper ◽  
A. Tamm ◽  
P. Tenjes ◽  
E. Tempel
Keyword(s):  
Elliptical Galaxies ◽  
Fundamental Relation ◽  
Noticeable Effect ◽  
Fundamental Plane ◽  
Velocity Dispersions

AbstractWe study the effect of environment to fundamental relation of elliptical galaxies. We find that superclusters, filaments and groups give noticeable effect to slope of velocity dispersions while little to luminosity slope.

scholarly journals The Stability of Axisymmetric Galaxy Models with Anisotropic Dispersions

1983 ◽  
Vol 100 ◽  
pp. 285-286
Author(s):  
Tim de Zeeuw ◽  
Marijn Franx ◽  
Jacques Meys ◽  
Karel Brink ◽  
Harm Habing
Keyword(s):  
Spiral Galaxies ◽  
Theoretical Models ◽  
Elliptical Galaxies ◽  
Small Class ◽  
Integrals Of Motion ◽  
Equilibrium Configurations ◽  
Velocity Dispersions ◽  
The Stability

The possible equilibrium configurations for elliptical galaxies and the bulges of spiral galaxies are no longer thought to be confined to the small class of axisymmetric systems with isotropic velocity dispersions. Many of these systems are not supported by rotation but instead by anisotropic velocity dispersions which are maintained by nonclassical integrals of motion (e.g., Binney 1978), and may be triaxial. Few theoretical models for such systems exist (Schwarzschild 1981). Here we discuss some axisymmetric models that we have constructed by means of Schwarzschild's (1979) selfconsistent method, and in particular their stability.

Evolution of dwarf galaxies in a semi-analytic galaxy formation model

2018 ◽  
Vol 14 (S344) ◽  
pp. 491-494
Author(s):  
Masahiro Nagashima ◽  
Motohiro Enoki ◽  
Tomoaki Ishiyama ◽  
Masakazu A. R. Kobayashi ◽  
Ryu Makiya ◽  
...  
Keyword(s):  
Galaxy Formation ◽  
Cold Dark Matter ◽  
Dwarf Galaxies ◽  
Elliptical Galaxies ◽  
Dynamical Response ◽  
Cold Dark Matter Model ◽  
Gas Removal ◽  
Dwarf Elliptical Galaxies ◽  
Velocity Dispersions ◽  
Dark Matter Model

AbstractDwarf galaxies provide us many important clues to understanding of galaxy formation. By using the current version of our own semi-analytic model of galaxy formation, in which cosmic structure forms and evolves based on the cold dark matter model of cosmology, we analyze dwarf galaxies. We find that the model well reproduces many properties such as magnitudes, sizes, and velocity dispersions of, especially, dwarf elliptical galaxies. We also find that the dynamical response of the gravitational potential well of dwarf galaxies to the supernova-induced gas removal plays a very important role to obtain large sizes and small velocity dispersions as observed.

scholarly journals The metallicities, velocity dispersions and true shapes of elliptical galaxies

1981 ◽  
Vol 196 (2) ◽  
pp. 381-395 ◽  
Author(s):  
R. Terlevich ◽  
R. L. Davies ◽  
S. M. Faber ◽  
D. Burstein
Keyword(s):  
Elliptical Galaxies ◽  
Velocity Dispersions
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