Free Access

Fig. 14

image

Filter functions taken from the ESO database. The black lines are for the Landolt filters, while the red lines are for the Gunn filters. The z filter does not have a cut-off in the red, but is instead limited by the quantum efficiency of the CCD, which drops to 10% at 1 μm.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.