21SSD: a public data base of simulated 21-cm signals from the epoch of reionization

International audienceThe 21-cm signal from the epoch of reionization (EoR) is expected to be detected in the next few years, either with existing instruments or by the upcoming SKA and HERA projects. In this context, there is a pressing need for publicly available high-quality templates covering a wide range of possible signals. These are needed both for end-to-end simulations of the up-coming instruments and to develop signal analysis methods. We present such a set of templates, publicly available, for download at 21ssd.obspm.fr. The data base contains 21-cm brightness temperature lightcones at high and low resolution, and several derived statistical quantities for 45 models spanning our choice of 3D parameter space. These data are the result of fully coupled radiative hydrodynamic high-resolution (1024^3) simulations performed with the licorice code. Both X-ray and Lyman line transfer are performed to account for heating and Wouthuysen–Field coupling fluctuations. We also present a first exploitation of the data using the power spectrum and the pixel distribution function (PDF) computed from lightcone data. We analyse how these two quantities behave when varying the model parameters while taking into account the thermal noise expected of a typical SKA survey. Finally, we show that the noiseless power spectrum and PDF have different – and somewhat complementary – abilities to distinguish between different models. This preliminary result will have to be expanded to the case including thermal noise. This type of results opens the door to formulating an optimal sampling of the parameter space, dependent on the chosen diagnostics