Astrophysics & Cosmology Sabine Schindler Institute for Astrophysics University of Innsbruck.
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Transcript of Astrophysics & Cosmology Sabine Schindler Institute for Astrophysics University of Innsbruck.
Astrophysics & Cosmology
Sabine Schindler Institute for Astrophysics
University of Innsbruck
Currently most active field of research in Innsbruck:Clusters of Galaxies
Largest bound structures Size ~ a few Mpc Mass ~ 1015 Msun
Observable to large distances
Ideal tools for cosmology
Cluster Components
GalaxiesIntra-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 amount of dark matter distribution of dark matterbut nature of dark matter still unknown!!!
Matter Density m of the Universe
Assumption: ratio of visible matter to Assumption: ratio of visible matter to dark matter in clusters is representative dark matter in clusters is representative for the universe as a whole for the universe as a whole
3.0min units of thecritical density
Structure Formation
Observations only snapshots (time scales ~ 109 yrs)
Numerical simulations follow the evolution
Different componentsgalaxies, dark matter N-bodygas hydrodynamic simulations
For movies see http://astro.uibk.ac.at/astroneu/hydroskiteam/index.htm
Comparison with Observations
X-rays:XMM-Newton (ESA)
De Filippis, Schindler, Castillo-Morales, 2003
optical:VLT (ESO)Erben, Miralles,
Schindler, Schneider, in prep.
From observations and simulations:• Dynamics • Evolution• Interaction of components• Heavy element enrichment• .....
Structure Formation and Evolution
Cosmology
Galaxy clusters – the largest bound structures in the universe