↩ 🔵 🔵 🔵 ❪✺❫ Astronomical Concepts ○ ❪✺❫ High-Energy Astrophysics Concepts ○ Accretion ○ ❪✺₁ᵢ❫ Accretion Classes ○ ❪✺_ᵢ❫ Accretion Subs ○ Advection-Dominated Accretion Flow (ADAF) ○ Geometric Thickness ○ Magnetorotational Instability (MRI) ○