Median RV (〈V_R〉) of FPR sources as a function of their galactic latitude. Red sources are C-star candidates. The solid lines indicate median values over bins of galactic latitude. The curves show the median value and standard deviation of 〈V_R〉 in bins of galactic latitude (for C-stars these statistics are limited to galactic longitudes between 30° and 330°, excluding regions where they are scarce).