Free Access

Fig. 4

thumbnail

Comparison of the He II 1640 Å (top: STIS spectrum) and 4868 Å (bottom: NOT spectrum) line profiles from Nov. 20/21. Note that the two spectral intervals were nearly simultaneous, making this comparison possible. The He II 4686 Å is severely blended but the line accounts for the excess emission. In the bottom panel, the He II 1640 Å line is shown (dashed line) for comparison scaled by the continuum flux.

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.