Today's Colloquium: Wide-field VLBI observations of the COSMOS field

© Noelia Herrera

Quantifying the fraction of AGN in the faint radio population is fundamental for studying galaxy evolution. A relatively easy and direct way to determine which galaxies do have a radio-active AGN is a detection using the Very Long Baseline Interferometry (VLBI) technique.

We have observed ~3000 radio sources in the COSMOS extragalactic field with the Very Long Baseline Array (VLBA) at 1.4GHz to study the faint radio source population with statistically relevant numbers. We have detected 468 sources.

The combination of number of sources, sensitivity, angular resolution and area covered by this project are unprecedented. In this overview I will present the survey design, observations, and calibration, along with the results of the project.