Cosmological simulations of the high - z radio universe 3

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 ∼ > 0.2, 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 cD 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 cm-wave surveys.