Open Access
Fig. 3.
Download original image
HR evolution during the three XMM-Newton observations of Vela X-1 compared to the orbit-averaged MAXI/GSC trend (2009–2024), adapted from Abalo et al. (2024). MAXI HRs, based on Crab-like spectra, appear systematically harder and are rescaled for comparison with XMM-Newton, which uses count-based HRs.
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.