Speaker
Description
Star-forming galaxies (SFGs) are the dominant population in the faint radio sky, corresponding to flux densities < 0.1 mJy. Understanding star formation processes across cosmic time requires a panchromatic approach. Semi-empirical models, relying on minimal assumptions and exploiting empirical relations between galaxy properties, are particularly powerful in this context, enabling us to take full advantage of recent progress in radio and optical/near-infrared (NIR) observations. We have developed the Semi-EMPirical model for Extragalactic Radio emission (SEMPER) to predict radio luminosity functions and number counts at 1.4 GHz and 150 MHz for SFGs. SEMPER combines redshift-dependent galaxy stellar mass functions derived from deep near-infrared (NIR) data with state-of-the-art empirical relations, such as the galaxy main sequence and the far-IR/radio correlation, with the goal of better understanding the radio properties of high-z, massive galaxy populations. The model has demonstrated excellent agreement with recent observations from the Very Large Array (VLA) and the Low-Frequency Array (LOFAR) at 1.4 GHz and 150 MHz, respectively. Notably, SEMPER naturally predicts the presence of a significant population of massive, dust-obscured galaxies already in place at high redshifts, as also suggested by recent JWST observations. This talk will present our semi-empirical framework and its predictive capabilities in the context of upcoming surveys conducted with the Square Kilometre Array Observatory (SKAO). The exceptional sensitivity and broad redshift coverage of the SKAO Low and Mid arrays will open a unique window onto the evolution of the cosmic star formation rate density, providing an unprecedented opportunity to refine SEMPER’s predictions.
| Topics | Galaxy Evolution & AGN |
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