Fig. 1

Download original image
Telluric spectrum for the observation day January 26, 2023. Top panel: the telluric spectrum (orange) used to correct the solar spectrum (blue). The green vertical line marks the position of the SiI line near the He triplet, while the gray band represents the region over which we fit the He triplet to extract its properties (see Sects. 3.2.2 and 3.2.3). The diagonal and anti-diagonal hashed regions indicate the range used to calculate the equivalent width (hereafter referred to as EW) of the SiI line and He triplet, respectively. Bottom panel: zoomed-in view of the region around the He triplet. The position of telluric H2O lines, obtained from the HITRAN database, are indicated by blue dashed vertical lines (Gordon et al. 2022). Notably, an H2O absorption line overlaps with the He triplet around 10 833.3 Å. The impact of this line on the He triplet is explored in Sect. 3.2.4 and discussed in Sect. 4.1. In both plots, red vertical lines denote the positions of the He triplet transitions.
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.