סמינר באסטרונומיה ובאסטרופיזיקה

Mr. Ilya Leitus:

Title:

DYNAMICS OF SHOCK WAVES WITH RADIATION DRAG

Abstract:

* Short Introduction

* Self similar solutions

* Numerical HD Simulations

and

Mr. Mark Mirmelstein

Title:

Detection of CMB polarization induced by clusters of galaxies

Abstract:

The hot intra-cluster (IC) gas in galaxy clusters comptonizes the cosmic microwave background (CMB) radiation, a process known as the thermal Sunyaev-Zel'dovich (SZ) effect. Similarly, the CMB temperature is slightly changed towards clusters due to radial motion along the line of sight via the kinematic SZ effect. The scattered CMB photons are also linearly polarized, the level and angular signature of which depend on cluster properties, potentially providing a unique handle on IC dynamics in transversal directions to the line of sight.

In this talk I will explore the little-discussed topic of detectability of CMB polarization induced by clusters of galaxies. Specifically,  the detectability of polarization towards clusters at various redshifts by three different ground-based CMB polarization experiments will be discussed. We used several types of numerical simulations of IC gas to obtain the polarization signals, and assessed the signal-to-noise for such detection in the presence of cosmological and astrophysical noise sources. Our results demonstrate marginal detection for nearby clusters.

מארגת הסמינר: פרופ' שרה בק