Oral Presentation
Emulating the 21cm global signal and analyzing the EDGES public data
Presenter: Shintaro Yoshiura (Mizusawa VLBI Observatory, NAOJ)
The 21cm line from neutral hydrogen atom is one of useful tool for probing the high-z universe filled with neutral gases. In particular, the evolution of the 21cm line brightness temperature is dependent on the properties of the first stars and galaxies. Thus, the observation of 21cm global signal can reveal the evolution of first stars and galaxies at the Cosmic Dawn. Statistical constraints on astronomical models require Bayesian MCMC analysis, but the prediction of the 21cm line is computationally expensive. Therefore, we created an emulator of the 21cm signal for fast and accurate prediction. In this study, we reanalyzed the publicly available EDGES data by using the developed emulator with various foreground and systematic models. Some of models favor an absorption at z=17.8. For creating the high-z absorption, however, extremely high star formation rate is required before z=18.
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