↩ 🔵 🔵 🔵 ❪✺_ₛₛ❫ High-Energy Astrophysics Subsets ○ ❪✺_ₜₛ❫ Astronomical Typesets ○ ❪✺_ₜₛ❫ Spectral Fitting Typesets ○ ❪𖣐₁’❫ X-Ray Data Products ○ ❪𖣐₂’❫ Gamma-Ray Observatories ○ ❪𖣐₂’❫ X-Ray Detectors ○ ❪𖣐₂’❫ X-Ray Observatories ○