Cosmological simulations of the high-redshift radio universe

Using self-consistent cosmological simulations of disc galaxy formation, we analyse the 1.4-GHz radio flux from high-redshift progenitors of present-day normal spirals within the context of present-day and planned next-generation observational facilities. We demonstrate that, while current radio facilities such as the Very Large Array (VLA) are unlikely to trace these progenitors beyond redshifts z ≳.2, future facilities such as the Square Kilometer Array (SKA) will readily probe their characteristics to redshifts z ≳ 2, and are likely to provide detections beyond z ≳ 3. We also demonstrate that the progenitors of present-day central dominant galaxies can emit in excess of 10 μJy of flux at redshifts z ≳ 1, and may be a non-negligible contributor to the micro-Jansky source counts derived from current deep VLA centimetre-wave surveys.