POLAR-I: linking the 21-cm signal from the epoch of reionization to galaxy formation

To self-consistently model galactic properties, reionization of the intergalactic medium, and the associated 21-cm signal, we have developed the algorithm polar by integrating the one-dimensional radiative transfer code grizzly with the semi-analytical galaxy formation code L-Galaxies 2020. Our proof-of-concept results are consistent with observations of the star formation rate history, UV luminosity function, and the CMB Thomson scattering optical depth. We then investigate how different galaxy formation models affect UV luminosity functions and 21-cm power spectra, and find that while the former are most sensitive to the parameters describing the merger of haloes, the latter have a stronger dependence on the supernovae feedback parameters, and both are affected by the escape fraction model.

Automated summary

To self-consistently model galactic properties, reionization of the intergalactic medium, and the associated 21-cm signal, an algorithm named polar has been developed by integrating the one-dimensional radiative transfer code grizzly with the semi-analytical galaxy formation code L-Galaxies 2020. The proof-of-concept results show good agreement with observations of the star formation rate history, UV luminosity function, and the CMB Thomson scattering optical depth. Additionally, the study investigates the impact of different galaxy formation models on UV luminosity functions and 21-cm power spectra, finding that halo merger parameters have the strongest influence on the former, while supernovae feedback parameters have a stronger dependence on the latter, and both are affected by the escape fraction model.