Free Access

Fig. A.1


Field of view without polarizer (9×9 arcmin) of HB89 2201+044. The white circles indicate the locations of the blazar (1) and field stars (>1). East is up and north is to the right.

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.