Mock catalog of extragalactic radio background

We also apply special treatments to reproduce the clustering signal of radio AGNs.Our empirical model successfully recovers the observed 1.4GHz radio luminosity functions (RLFs) of both AGN and SFG populations, as well as the differential number counts at various radio bands. The uniqueness of this approach also allows us to directly link radio flux densities of galaxies to other properties, including redshifts, stellar masses, and magnitudes at various photometric bands.

We find that roughly half of the radio continuum sources to be detected by the Square Kilometer Array (SKA) at z~4-6 will be too faint to be detected in the optical survey (r~27.5) carried out by Rubin observatory.Unlike previous studies which utilized (extrapolations of) RLFs to reproduce ERB, our work starts from a simulated galaxy catalog with realistic physical properties. It has the potential to simultaneously, and self-consistently reproduce physical properties of galaxies across a wide range of wavelengths, from optical, NIR, far-infrared (FIR) to radio wavelengths.

Our empirical model can shed light on the contribution of different galaxies to the extragalactic background light, and greatly facilitates designing future multiwavelength galaxy surveys.