Identifying Galaxy clusters from CMB maps using the Sunyav-Zeldovich effect.

by Carlos Alexandre Wuenske

Thursday 2 Dec 2010, 16:00 → 18:00 Europe/Rome

Aula Conversi (Dipartimento di Fisica - Ed. G. Marconi)

Abstract: The cosmic microwave background (CMB) can be used to probe the processes of structure formation in the Universe. Secondary CMB anisotropies mask the primary signal and contaminate the measurements of the intrinsec signal. The Sunyaev-Zeldovich (SZ) effect, the most important of these processes (inverse Compton scattering of CMB photons by hot electrons in the core of galaxy clusters), is used for cosmological studies of the Hubble constant, the mass fraction of gas in galaxy clusters and the ω-parameter in the dark energy equation of state. We present here the results of simulations to recover SZ clusters from CMB datasets produced by the Planck satellite. Synthetic clusters generated from isothermal-beta profiles are combined to a CMB sky plus Galactic foregrounds and instrumental noise. We performed a blind survey in the maps to test an ICA-based algorithm known as JADE (Joint Approximate Diagonalization of Eigenmatrices). This is a very efficient method to recover the cluster amplitude and position, (90% of the included clusters). We are working on extracting cosmological information from these dataset (dN/dz) and simulate the effect of different cosmologies in the extracted cosmological parameters.