Author(s) :

Dev Narain Kushangi.

Volume/Issue :

Abstract :

This review examines the formation of stellar-mass black holes as the endpoint of massive star evolution. As massive stars progress through successive stages of nuclear burning, they develop iron cores that can no longer be supported under typical stellar conditions by thermal pressure or electron degeneracy pressure. This ultimately leads to gravitational collapse under standard stellar evolution models. Collapse of this core can result in either a neutron star or a black hole, depending on a combination of factors such as metallicity, mass loss, rotation, binary interaction, shock revival mechanisms, and fallback accretion. Recent neutrino-driven core-collapse supernova simulations indicate that black holes do not occur above a single mass threshold, but instead along complex regions characterized by “islands of explodability” and failed-explosion pathways. This review combines theoretical and computational models of core collapse, failed explosion, fallback collapse to black holes, and direct collapse, and connects these processes to observational constraints from X-ray binaries, supernova remnants, gravitational-wave observations, and multimessenger astrophysics. Significant uncertainties remain, particularly regarding the remnant mass distribution, the importance of multidimensional effects, rotation, magnetic fields, and binary evolution. Black hole formation therefore remains a central problem linking stellar evolution, supernova theory, compact-object demographics, and strong-gravity astrophysics.