Median of the proper motion of quasars included in the catalogs PPMXL and 2MASS. Bin size: 15 deg × 15 deg in Galactic coordinates. Green to violet indicates positive values; brown to orange indicates negative values; darkest colors indicate that there are fewer than 20 quasars in that bin, therefore no median was calculated.
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.