Search Publications
The evolution of cluster early-type galaxies over the past 8 Gyr
Fritz, A.; Jørgensen, I.; Schiavon, R. P. +1 more
We present the Fundamental Plane (FP) of early-type galaxies in the clusters of galaxies RXJ1415.1+3612 at z=1.013. This is the first detailed FP investigation of cluster early-type galaxies at redshift z=1. The distant cluster galaxies follow a steeper FP relation compared to the local FP. The change in the slope of the FP can be interpreted as a…
NGC 1275: Baryonic cycling in the Perseus cluster of galaxies
Gallagher, J. S.
NGC 1275, the central galaxy of the Perseus cluster, contains a remarkable cool ISM. This gas is arrayed in a series of filaments extending over 30 kpc with an extension of 70 kpc to the north. These emit substantial cooling line radiation from H II, a hot H_2 zone, and CO in a cool molecular region which contains most of the gas mass. This contri…
Smooth, undisturbed dwarf spheroidal galaxies in the Perseus cluster core: Implications for dark matter content
Held, E. V.; Conselice, C. J.; De Rijcke, S. +1 more
Using deep HST/ACS observations of the core of the Perseus Cluster, we identify a large population of dwarf elliptical galaxies down to MV = -12. All these dwarfs are remarkably smooth in appearance, showing no evidence for internal features that could be the result of tidal processes or star formation induced by the cluster potential. …
The evolution of spheroidal galaxies in different environments
Ziegler, B. L.; Fritz, A.
We analyse the kinematic and chemical evolution of 203 distant spheroidal (elliptical and S0) galaxies at 0.2<z<0.8 which are located in different environments (rich clusters, low-mass clusters and in the field). VLT/FORS and CAHA/MOSCA spectra with intermediate-resolution have been acquired to measure the internal kinematics and stellar pop…
The evolution of cluster dwarfs
Harsono, D.; De Propris, R.
We summarize the results from analyzing six clusters of galaxies at 0.14 < z < 0.40 observed with the Hubble Space Telescope Advanced Camera for Surveys. We derive deep composite luminosity functions in B, g, V, r, i, and z down to absolute magnitude of ∼ -14 + 5 log h mag. The luminosity functions are fitted by a single Schechter function w…
A multi-wavelength view of the archetypical CSS radio galaxy 3C303.1: Evidence for shocks and induced star formation
O'Dea, C. P.
I discuss multi-wavelength data on the archetypal CSS radio galaxy 3C303.1. The radio source is sub-galactic in scale where it can directly affect the ISM of the host galaxy. The emission line kinematics and ionization diagnostics are consistent with energy input from shocks driven by the radio source. The Spitzer IRS spectrum indicates that star …
Evolution of dwarf galaxies in the Centaurus A group
Crnojević, D.; Grebel, E. K.; Koch, A.
The study of (dwarf) galaxies in nearby groups is one among the most powerful tools that can be used to investigate galaxy evolution, chemical enrichment and environmental effects on these objects. The Centaurus A group (at a distance of ∼ 4 Mpc) is dynamically evolved and contains about 30 dwarf companions of different morphologies and stellar co…
Dwarf spheroidal galaxies in the M81 group of galaxies
Grebel, E. K.; Koch, A.; Lianou, S.
We study the properties of the dwarf galaxy population in the nearby interacting M81 group of galaxies. In particular, we are deriving the metallicity distribution functions, the ages and the star formation histories of these dwarf galaxies based on data from the Hubble Space Telescope's Advanced Camera for Surveys and the Sloan Digital Sky Survey…
Galaxy-galaxy interactions as triggers of star formation
Popescu, N. A.
Galaxy-galaxy interactions represent the main physical processes that trigger substantial star formation in galaxies. In order to study the galaxy interactions effects on color and morphology of the galaxies in the fields of two radio galaxies at z∼ 1, we combined optical-NIR photometry and HST/WFPC2 morphology data from the Stanford et al. (2002)…