↩ 🔵 🔵 🔵 ❪✺❫ HEASoft Concepts ○ ❪✺₃❫ High-Energy Astrophysics Particulars ○ HEASoft ○˒ ❪✺₃❫ XSPEC Particulars ○ XSELECT ○˒ XSPEC ○͒ XSTAR ○˒