Covering host systems of accreting, relativistic bodies, and the high-energy phenomena associated with them, this self-contained astrophysics textbook is ideal for advanced undergraduates. The textbook introduces students to a unique blend of astrophysical principles, including the evolutionary history of compact binary stars, the physics of accretion and accretion disc outbursts, the observed signatures of such discs in binary stars and active galactic nuclei, the X-ray emission of accreting compact bodies, and the physics of astrophysical jets and gamma-ray bursts. Worked examples,...