Behaviour of 12 + log (Ar/H) vs. 12 + log (O/H). In red the H ii regions. The linear fits, including only PNe, corresponds to 12 + log (Ar/H) = (−0.494 ± 0.512) + (0.768 ± 0.064) × (12 + log (O/H)), with r = 0.79. The stellar evolution models for Z = 0.001 by Fishlock et al. (2014, F14) are included.
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.