The Gravothermal Instability at All Scales: From Turnaround Radius to Supernovae

Autor: Zacharias Roupas
Jazyk: angličtina
Rok vydání: 2019
Předmět:
Zdroj: Universe, Vol 5, Iss 1, p 12 (2019)
Druh dokumentu: article
ISSN: 2218-1997
DOI: 10.3390/universe5010012
Popis: The gravitational instability, responsible for the formation of the structure of the Universe, occurs below energy thresholds and above spatial scales of a self-gravitating expanding region, when thermal energy can no longer counterbalance self-gravity. I argue that at sufficiently-large scales, dark energy may restore thermal stability. This stability re-entrance of an isothermal sphere defines a turnaround radius, which dictates the maximum allowed size of any structure generated by gravitational instability. On the opposite limit of high energies and small scales, I will show that an ideal, quantum or classical, self-gravitating gas is subject to a high-energy relativistic gravothermal instability. It occurs at sufficiently-high energy and small radii, when thermal energy cannot support its own gravitational attraction. Applications of the phenomenon include neutron stars and core-collapse supernovae. I also extend the original Oppenheimer–Volkov calculation of the maximum mass limit of ideal neutron cores to the non-zero temperature regime, relevant to the whole cooling stage from a hot proto-neutron star down to the final cold state.
Databáze: Directory of Open Access Journals