Distribution of HII regions with photometric (blue) or trigonometric (red) distances. Two black stars indicate the location of the Sun (x = 0.0 kpc, y = 8.5 kpc) and the GC (x = 0.0 kpc, y = 0.0 kpc). Q1−Q4 indicate the four Galactic quadrants. Position uncertainties are indicated by error bars in X and Y directions.
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.