Smoot Lensing Subgroup




Experiments in Gravitational Lensing

Supernova Magnification

Three of the Supernova from the current Hubble Deep Field(HDF) survey are behind or near massive galaxy clusters. We suspect that these clusters will significantly magnify the SNe image. We intend to determine this magnification.

Drizzle Images. Determine mass distribution of the cluster using a method known only as NFW. Use theoretical model to determine the magnification.

For the velocity dispersion of cluster CLG 1236+6215 (1), we fit a gaussian to the histogram(below), which is Number of Galaxies vs. Velocities. The standard deviation of gaussian should be our velocity dispersion. Once we have the velocity dispersion, we will be able to use the Virial Theorem to determine the mass of the cluster.

fig. 1


Weak Lensing

Determine the dark matter mass distribution for clusters in the current HDF survey.

We will use two methods(1. KSB 2. Shapelets) and then compare the results.

(1)We use the redshifts given by Dawson et al. 2001