Low mass SN Ia and the late light curve Metadata

Title

• Main Title Low mass SN Ia and the late light curve

Creator

• Author: Colgate, S. A.
  Creator Type: Personal
  Creator Info: Los Alamos National Lab., NM (United States)
• Author: Fryer, C. L.
  Creator Type: Personal
  Creator Info: Univ of Arizona, Tucson, AZ (United States). Steward Observatory
• Author: Hand, K. P.
  Creator Type: Personal
  Creator Info: Dartmouth Coll., Hanover, NH (United States)

Contributor

• Sponsor: United States. Department of Energy.
  Contributor Type: Organization
  Contributor Info: USDOE, Washington, DC (United States)
• Sponsor: United States. Department of Defense.
  Contributor Type: Organization
  Contributor Info: Department of Defense, Washington, DC (United States)

Publisher

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

Date

• Creation: 1995-12

Language

• English

Description

• Content Description: The late bolometric light curves of type Ia supernovae, when measured accurately over several years, show an exponential decay with a 56d half-life over a drop in luminosity of 8 magnitudes (10 half-lives). The late-time light curve is thought to be governed by the decay of Co{sup 56}, whose 77d half-life must then be modified to account for the observed decay time. Two mechanisms, both relying upon the positron fraction of the Co{sup 56} decay, have been proposed to explain this modification. One explanation requires a large amount of emission at infra-red wavelengths where it would not be detected. The other explanation has proposed a progressive transparency or leakage of the high energy positrons (Colgate, Petschek and Kriese, 1980). For the positrons to leak out of the expanding nebula at the required rate necessary to produce the modified 56d exponential, the mass of the ejecta from a one foe (10{sup 51} erg in kinetic energy) explosion must be small, M{sub ejec} = 0.4M{sub {circle_dot}} with M{sub ejec} {proportional_to} KE{sup 0.5}. Thus, in this leakage explanation, any reasonable estimate of the total energy of the explosion requires that the ejected mass be very much less than the Chandrasekhar mass of 1.4M{sub {circle_dot}}. This is very difficult to explain with the ``canonical`` Chandrasekhar-mass thermonuclear explosion that disintegrates the original white dwarf star. This result leads us to pursue alternate mechanisms of type Ia supernovae. These mechanisms include sub-Chandrasekhar thermonuclear explosions and the accretion induced collapse of Chandrasekhar mass white dwarfs. We will summarize the advantages and disadvantages of both mechanisms with considerable detail spent on our new accretion induced collapse simulations. These mechanisms lead to lower Ni{sup 56} production and hence result in type Ia supernovae with luminosities decreased down to {approximately} 50% that predicted by the ``standard`` model.
• Physical Description: 35 p.

Subject

• Keyword: Thermonuclear Explosions
• Keyword: Supernovae
• Keyword: Mathematical Models
• Keyword: Gamma Radiation
• Keyword: Positrons
• STI Subject Categories: 66 Physics
• Keyword: Chandrasekhar Theory
• Keyword: Astrophysics
• Keyword: Supernova Remnants

Source

• Conference: NATO advanced study institute conference on thermonuclear supernovae, Barcelona (Spain), 19-30 Jun 1995

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: DE96005068
• Report No.: LA-UR--95-4080
• Report No.: CONF-9506311--1
• Grant Number: W-7405-ENG-36
• Office of Scientific & Technical Information Report Number: 204639
• Archival Resource Key: ark:/67531/metadc669155

Note

• Display Note: INIS; OSTI as DE96005068