High angular resolution SZ observations with NIKA

by Barbara Comis (Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, Grenoble, France)

Monday 18 May 2015, 14:00 → 15:00 Europe/Rome

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

Clusters of galaxies represent the largest gravitationally bound objects that we can observe in our Universe and a strong complementary tool for the cosmological investigation. Most of the cluster baryons are present as a diffuse gas, whose electrons can Compton inverse interact with CMB photons producing the thermal Sunyaev-Zel’dovich (SZ) effect (a distortion of the CMB black-body spectrum at the cluster position). In the last years survey dedicated instruments (Planck, ACT, SPT) have finally produced SZ-selected catalogues containing hundreds of clusters. However, cluster derived cosmology is limited by our ability to translate the SZ flux into mass estimates and tracers of the matter distribution. This is why, with the final instrument NIKA2, at the focus of the IRAM 30m telescope, the NIKA collaboration will perform a systematic high-angular resolution SZ follow-up of a representative sample of intermediate and high-redshift clusters. NIKA, the NIKA2 prototype, has already produced high-quality SZ observations.