FAUST observations in the Fourth Galactic Quadrant

We analyse UV observations with FAUST of four sky fields in the general direction of the Fourth Galactic Quadrant, in which we detect 777 UV sources. This is ∼50 per cent more than detected originally by Bowyer et al. We discuss the source detection process and the identification of UV sources with optical counterparts. For the first time in this project we use ground-based objective-prism information for two of the fields, to select the best-matching optical objects with which to identify the UV sources. Using this, and correlations with existing catalogues, we present reliable identifications for ∼75 per cent of the sources. Most of the remaining sources have assigned optical counterparts but, lacking additional information, we offer only plausible identifications. We discuss the types of objects found, and compare the observed population with predictions of our UV Galaxy model.