"The solar X-ray images are from the Yohkoh mission. Yohkoh is a Japan/US/UK mission for high-energy solar physics. The X-ray telescope was prepared by the Lockheed-Martin Solar and Astrophysics Laboratory, the National Astronomical Observatory of Japan, and the University of Tokyo with the support of NASA and ISAS/JAXA."
If an SXT image is displayed in a popular article, on a website, etc., then please acknowledge the contributing institutions: (JAXA/NASA/MSSL).