Using 21 cm emission to study the Epoch of Reionization with SKA

by Mr Benoit Semelin (LERMA, Paris Observatory)

Tuesday 26 May 2009, 13:15 → 14:15 Europe/Stockholm

FB54

In the next decade the Square Kilometer Array and its pathfinders (LOFAR, MWA, etc...) will be able to observe the 21cm radiation emitted by neutral hydrogen during the Epoch of Reionization. These observations will teach us a lot about the nature and formation history of the first sources of light, and will yield consrtaints on cosmological models. To be able to optimize the instrument design and interpret the future observations, we need an accurate modeling of the 21cm signal. I will first present the physics of the 21 cm emission and the prospects for detection by these future radio-interferometers. Then I will explain how the nature of the sources and the state of the intergalactic medium can alter the statistical properties of the signal. In the framework of the SKA Design Study, we performed hydrodynamical and radiative transfer simulations in a cosmological context to predict the 21cm signal. In addition to the ionizing radiation, we also compute the full 3D radiative transfer for Lyman-alpha photons, needed to compute correctly the 21-cm signal. I will present emission maps and power spectra for the signal and suggestions for an improved design of future instruments.