Free Access
Fig. 16
Number of Ca ii and Na i absorption systems versus their equivalent width. The dashed line represents the equivalent width of Wλ = 300 km s-1, which separates weak from strong absorption systems according to Mg ii systems.
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.