X-Ray Properties of Black-Hole Binaries

TLDR

The larger majority of accreting black‑hole X‑ray binaries are transients observed daily with RXTE throughout their outbursts. The paper reviews the properties and behavior of these binaries and sketches a scenario for their impact on physics, including the measurement of black‑hole spin. The review describes the complex evolution of these systems through common behavior patterns illustrated with overview diagrams for six selected binaries, focusing on three quantitatively defined X‑ray accretion states. The authors find that each of the three accretion states produces phenomena arising in strong gravitational fields, and they outline how black‑hole observations can impact physics, notably through spin measurements.

Abstract

We review the properties and behavior X-ray binaries that contain an accreting black hole. The larger majority of such systems are X-ray transients, and many of them were observed in daily pointings with RXTE throughout the course of their outbursts. The complex evolution of these sources is described in terms of common behavior patterns illustrated with comprehensive overview diagrams for six selected systems. Central to this comparison are three X-ray states of accretion, which are reviewed and defined quantitatively. Each state yields phenomena that arise in strong gravitational fields. We sketch a scenario for the potential impact of black hole observations on physics and discuss a current frontier topic: the measurement of black hole spin.