Astrophysical Black Holes

TL;DR

Black holes are widespread cosmic objects with significant observational evidence, influencing galaxy evolution, and their properties can be understood through general relativity, with ongoing research into their thermodynamics and energy extraction.

Contribution

This paper provides a comprehensive review of black hole observations, properties, and theoretical foundations, highlighting recent advances and future research directions.

Findings

Evidence for 4 million Solar mass black hole at Galactic center

Black hole accretion produces luminous quasars

Discussion of black hole thermodynamics and energy extraction

Abstract

Black holes are a common feature of the Universe. They are observed as stellar mass black holes spread throughout galaxies and as supermassive objects in their centres. Observations of stars orbiting close to the centre of our Galaxy provide detailed clear evidence for the presence of a 4 million Solar mass black hole. Gas accreting onto distant supermassive black holes produces the most luminous persistent sources of radiation observed, outshining galaxies as quasars. The energy generated by such displays may even profoundly affect the fate of a galaxy. We briefly review the history of black holes and relativistic astrophysics before exploring the observational evidence for black holes and reviewing current observations including black hole mass and spin. In parallel we outline the general relativistic derivation of the physical properties of black holes relevant to observation. Finally we speculate on future observations and touch on black hole thermodynamics and the extraction of energy from rotating black holes.