scholarly journals Cosmological Parameters from the SDSS DR5 Velocity Dispersion Function of Early-Type Galaxies through Radio-selected Lens Statistics

2007 ◽  
Vol 658 (2) ◽  
pp. L71-L74 ◽  
Author(s):  
Kyu-Hyun Chae
2003 ◽  
Vol 594 (1) ◽  
pp. 225-231 ◽  
Author(s):  
Ravi K. Sheth ◽  
Mariangela Bernardi ◽  
Paul L. Schechter ◽  
Scott Burles ◽  
Daniel J. Eisenstein ◽  
...  

Author(s):  
Shuaibo Geng ◽  
Shuo Cao ◽  
Yuting Liu ◽  
Tonghua Liu ◽  
Marek Biesiada ◽  
...  

Abstract The redshift distribution of galactic-scale lensing systems provides a laboratory to probe the velocity dispersion function (VDF) of early-type galaxies (ETGs) and measure the evolution of early-type galaxies at redshift z ∼ 1. Through the statistical analysis of the currently largest sample of early-type galaxy gravitational lenses, we conclude that the VDF inferred solely from strong lensing systems is well consistent with the measurements of SDSS DR5 data in the local universe. In particular, our results strongly indicate a decline in the number density of lenses by a factor of two and a 20% increase in the characteristic velocity dispersion for the early-type galaxy population at z ∼ 1. Such VDF evolution is in perfect agreement with the ΛCDM paradigm (i.e., the hierarchical build-up of mass structures over cosmic time) and different from ”stellar mass-downsizing” evolutions obtained by many galaxy surveys. Meanwhile, we also quantitatively discuss the evolution of the VDF shape in a more complex evolution model, which reveals its strong correlation with that of the number density and velocity dispersion of early-type galaxies. Finally, we evaluate if future missions such as LSST can be sensitive enough to place the most stringent constraints on the redshift evolution of early-type galaxies, based on the redshift distribution of available gravitational lenses.


2020 ◽  
Vol 15 (S359) ◽  
pp. 62-66
Author(s):  
Carlo Cannarozzo ◽  
Carlo Nipoti ◽  
Alessandro Sonnenfeld ◽  
Alexie Leauthaud ◽  
Song Huang ◽  
...  

AbstractThe evolution of the structural and kinematic properties of early-type galaxies (ETGs), their scaling relations, as well as their stellar metallicity and age contain precious information on the assembly history of these systems. We present results on the evolution of the stellar mass-velocity dispersion relation of ETGs, focusing in particular on the effects of some selection criteria used to define ETGs. We also try to shed light on the role that in-situ and ex-situ stellar populations have in massive ETGs, providing a possible explanation of the observed metallicity distributions.


2009 ◽  
Vol 5 (H15) ◽  
pp. 67-67
Author(s):  
Robert N. Proctor ◽  
Duncan A. Forbes ◽  
Aaron J. Romanowsky ◽  
Jean P. Brodie ◽  
Jay Strader ◽  
...  

We detail an innovative new technique for measuring the 2-D velocity moments (rotation velocity, velocity dispersion and Gauss-Hermite coefficients h3 and h4) using spectra from Keck DEIMOS multi-object spectroscopic observations. The data are used to reconstruct 2-D rotation velocity maps.


2011 ◽  
Vol 737 (2) ◽  
pp. L31 ◽  
Author(s):  
Rachel Bezanson ◽  
Pieter G. van Dokkum ◽  
Marijn Franx ◽  
Gabriel B. Brammer ◽  
Jarle Brinchmann ◽  
...  

2006 ◽  
Vol 2 (S235) ◽  
pp. 88-89
Author(s):  
Dalia Chakrabarty

The estimation of the distribution of the total (luminous and dark) mass in early type systems is hard! Even for the lucky few systems for which kinematic information is available, its implementation is mired in problems, given uncertainties about the assumptions that enter the calculations; the most critical of such assumptions involve considerations of the system geometry and the shape of its velocity ellipsoid. This work offers an independent means of getting to the mass distributions of early type galaxies, without relying directly on the phase space distribution function. The methodology is based upon the well established idea that in elliptical galaxies, the largest variations in normalised velocity dispersion profiles occur typically at R < 0.5Re (Re≡ half-light radius) and at R ≥ 2Re.


1999 ◽  
Vol 186 ◽  
pp. 367-373
Author(s):  
P. Hickson

This paper reviews some of the outstanding questions concerning compact groups of galaxies. These relate to the physical nature and dynamical status of the groups, their formation and evolution, and their role in galaxy evolution. The picture that emerges is that compact groups are generally physically dense systems, although often contaminated by optical projections. Their evolution is likely a continuous process of infall, interaction and merging. As new galaxies are added, and previous ones merge, the membership of the group evolves. I suggest that while the size of the group changes little, other physical properties such as total mass, gas mass, velocity dispersion, fraction of early-type galaxies increase with time. This picture is at least qualitatively consistent with observations and provides a natural explanation for the strongest correlations found in compact group samples.


2020 ◽  
Vol 500 (1) ◽  
pp. 1343-1349
Author(s):  
K Sruthi ◽  
C D Ravikumar

ABSTRACT We present correlations involving central intensity ratio (CIR) of 52 early-type galaxies, including 24 ellipticals and 28 lenticulars, selected from low-density environment in the nearby (&lt;30 Mpc) universe. CIR is found to be negatively and significantly correlated with the mass of the central supermassive black hole, central velocity dispersion, absolute B-band magnitude, stellar bulge mass, and central Mg2 index of the host galaxy. The study proposes the use of CIR as a simple, fast, and efficient photometric tool for exploring the co-evolution scenario existing in galaxies.


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