Informazioni sull’evento


Coffee talks

Friday 22/01/2021 @ 11:30, On-line -

Matteo Bonato (IRA-INAF), "New constraints on the 1.4 GHz source number counts and luminosity functions in the Lockman Hole field"

I will present a study of the 1173 sources brighter than S_1.4GHz = 120 µJy detected over an area of ?1.4 deg^2 in the Lockman Hole field. Exploiting the multi-band information available in this field for ?79% of the sample, sources have been classified into radio loud (RL) active galactic nuclei (AGNs), star forming galaxies (SFGs) and radio quiet (RQ) AGNs, using a variety of diagnostics available in the literature. Exploiting the observed tight anti-correlations between IRAC band 1 or band 2 and the source redshift, a redshift was assigned to 177 sources missing a spectroscopic measurement or a reliable photometric estimate. A Monte Carlo approach was used to take into account the spread around the mean relation. The derived differential number counts and luminosity functions at several redshifts of each population show a good consistency with models and with earlier estimates made using data from different surveys and applying different approaches. Such results confirm that below ? 300 µJy SFGs+RQ AGNs overtake RL AGNs that dominate at brighter flux densities. Earlier indications of a similar evolution of RQ AGNs and SFGs were confirmed as well. Finally, I will discuss the angular correlation function of these sources and highlight its sensitivity to the criteria used for the classification.