Studying Galaxy Clusters with Weak Lensing
|Date/Time:||Friday, 09 Dec 2011 from 4:10 pm to 5:00 pm|
Talk by Melanie Simet, University of Chicago Department of Astronomy and Astrophysics.
Galaxy cluster counts are a powerful tool to constrain cosmological
parameters. To use their full potential, however, we must understand
their mass function. Weak lensing lets us measure the gravitational
mass directly, without making assumptions of the exact baryonic
physics of the cluster. I present our results from Stripe 82 of the
Sloan Digital Sky Survey, a region observed multiple times and coadded
to achieve greater depth. We measure the mass-optical richness
relation for 492 clusters. We also make a detection of tomography, the
effect that the lensing strength varies with the distance to the
lensed object so galaxies of different redshifts are sheared at
different levels. I also show some of the next steps to reducing the
errors in our current methods as a way forward to precision cosmology.