Astrophysics Cosmology Sabine Schindler Institute for Astrophysics University
Astrophysics & Cosmology Sabine Schindler Institute for Astrophysics University of Innsbruck
Currently most active field of research in Innsbruck: Clusters of Galaxies Ø Ø Largest bound structures Size ~ a few Mpc Mass ~ 1015 Msun Observable to large distances Ideal tools for cosmology
Cluster Components Ø Galaxies Ø Intra-cluster gas – Density ~ 10 -2 – 10 -4 cm-3 – Temperature ~ 107 -108 K – Thermal bremsstrahlung X-ray emission luminosity ~ 1043 -45 erg/s optical X-rays
Mass fraction Observable in Galaxies 3– 5% Optical Intra-cluster gas 15 – 20 % X-rays Dark matter Rest - We can measure Ø amount of dark matter Ø distribution of dark matter but nature of dark matter still unknown!!!
Matter Density m of the Universe Ø Assumption: ratio of visible matter to dark matter in clusters is representative for the universe as a whole in units of the critical density
Structure Formation Observations only snapshots (time scales ~ 109 yrs) Numerical simulations follow the evolution Different components Ø galaxies, dark matter Ø gas N-body hydrodynamic simulations
For movies see http: //astro. uibk. ac. at/astroneu/hydroskiteam/index. htm
Comparison with Observations optical: VLT (ESO) X-rays: XMM-Newton (ESA) Erben, Miralles, Schindler, Schneider, in prep. De Filippis, Schindler, Castillo-Morales, 2003
Galaxy clusters – the largest bound structures in the universe From observations and simulations: • Dynamics • Evolution • Interaction of components • Heavy element enrichment • . . . Structure Formation and Evolution Cosmology
- Slides: 13