The entropy in supernova explosions Metadata

Title

• Main Title The entropy in supernova explosions

Creator

• Author: Colgate, S. A.
  Creator Type: Personal

Contributor

• Sponsor: United States. Department of Energy. Office of Energy Research.
  Contributor Type: Organization
  Contributor Info: DOE/ER

Publisher

• Name: Los Alamos National Laboratory
  Place of Publication: New Mexico
  Additional Info: Los Alamos National Lab., NM (USA)

Date

• Creation: 1990-12-06

Language

• English

Description

• Content Description: The explosion of a supernova forms because of the collapse to a neutron star. In addition an explosion requires that a region of relatively high entropy be in contact with the neutron star and persisting for a relatively protracted period of time. The high entropy region ensures that the maximum temperature in contact with the neutron star and in hydrostatic equilibrium is less than some maximum. This temperature must be low enough such that neutrino emission cooling is small, otherwise the equilibrium atmosphere will collapse adding a large accretion mass to the neutron star. A so-called normal explosion shock that must reverse the accretion flow corresponding to a typical stellar collapse must have sufficient strength or pressure to reverse this flow and eject the matter with 10{sup 51} ergs for a typical type II supernova. Surprisingly the matter behind such a shock wave has a relatively low entropy low enough such that neutrino cooling would be orders of magnitude faster than the expansion rate. The resulting accretion low would be inside the Bondi radius and result in free-fall accretion inside the expanding rarefaction wave. The accreted mass or reimplosion mass unless stopped by a high entropy bubble could than exceed that of bound neutron star models. In addition the explosion shock would be overtaken by the rarefaction wave and either disappear or at least weaken. Hence, a hot, high entropy bubble is required to support an equilibrium atmosphere in contact with a relatively cold neutron star. Subsequently during the expansion of the high entropy bubble that drives or pushes on the shocked matter, mixing of the matter of the high entropy bubble and lower entropy shock-ejected matter is ensured. The mixing is driven by the negative entropy gradient between the high entropy bubble accelerating the shocked matter and the lower entropy of the matter behind the shock.
• Physical Description: 10 pages

Subject

• Keyword: Eruptive Variable Stars
• Keyword: Star Evolution
• Keyword: Physical Properties
• Keyword: Supernovae
• Keyword: Neutron Stars
• Keyword: Elementary Particles
• Keyword: Neutrinos
• Keyword: Variable Stars 640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar, Radio & X-Ray Sources
• Keyword: Massless Particles
• Keyword: Fermions
• Keyword: Star Accretion
• STI Subject Categories: 71 Classical And Quantum Mechanics, General Physics
• Keyword: Stars
• Keyword: Shock Waves
• Keyword: Leptons
• Keyword: Thermodynamic Properties
• Keyword: Entropy
• Keyword: Explosions

Source

• Conference: ESO/EIPC workshop: SN1987A and other supernova, Isola d'Elba (Italy), 17-22 Sep 1990

Collection

• Name: Office of Scientific & Technical Information Technical Reports
  Code: OSTI

Institution

• Name: UNT Libraries Government Documents Department
  Code: UNTGD

Resource Type

• Article

Format

• Text

Identifier

• Other: DE91005876
• Report No.: LA-UR-90-4264
• Report No.: CONF-9009320--1
• Grant Number: W-7405-ENG-36
• Office of Scientific & Technical Information Report Number: 6212049
• Archival Resource Key: ark:/67531/metadc1104690

Note

• Display Note: OSTI; NTIS; INIS; GPO Dep.