Constraining the EoR model parameters with the 21cm bispectrum

Abstract

We perform a Fisher analysis to estimate the expected constraints on the Epoch of Reionization (EoR) model parameters (i.e., minimum virial temperature, the ionizing efficiency and the mean free path of ionizing photons) taking into account the thermal noise of the exisitting telescopes, MWA and LOFAR. We consider how the inclusion of the 21cm bispectrum improves the constraints compared to using the power spectrum alone. Assuming that we perfectly remove the foreground, we found that the bispectrum, which is calculated by the 21cmFAST code, can constrain the EoR model parameters more tightly than the power spectrum since the bispectrum is more sensitive to the EoR model parameters than the power spectrum. We also found that degeneracy between the EoR model parameters can be broken by combining the bispectrum with the power spectrum.