Far beyond stacking: Fully bayesian constraints on sub-microJy radio source populations over the XMM-LSS-VIDEO field

Understand

Measuring radio source counts is critical for characterizing new extragalactic populations, brings a wealth of science within reach and will inform forecasts for SKA and its pathfinders.

• Yet there is currently great debate (and few measurements) about the behaviour of the 1.4-GHz counts in the microJy regime.
• One way to push the counts to these levels is via 'stacking', the covariance of a map with a catalogue at higher resolution and (often) a different wavelength.
• For the first time, we cast stacking in a fully bayesian framework, applying it to (i) the SKADS simulation and (ii) VLA data stacked at the positions of sources from the VIDEO survey.