.Ia type supernova

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Type .Ia supernovae are a subgroup of thermonuclear supernovae. The thermonuclear supernovae of type Ia arise when white dwarfs exceed the Chandrasekhar limit mass and the degenerative pressure cannot prevent the self-gravity from collapsing. The collapse of white dwarfs consisting of carbon and oxygen causes an explosive burning of the carbon and the energy released in the process completely destroys the degenerated star. As Super Nova type .Ia Type Ia supernovae are designated whose luminosity reach only one-tenth of the normal SN Ia. This property is attributed to an unstable ignition of the helium burning near the surface of a white dwarf in an AM Canum Venaticorum star .

AM Canum Venaticorum stars are a subgroup of cataclysmic variables consisting of two white dwarfs in which the more massive degenerate star accretes matter from the lighter white dwarf . The helium-rich matter initially leads to a stable helium burning on the surface of the white dwarfs, during which the interacting binary star system is observed as a super-soft X-ray source . In the course of development, the accretion rate drops and nuclear fusion ceases. In the AM-CVn system, around 10 helium flashes occur in the following million years , during which the helium is explosively ignited. This process corresponds to the nova outbursts in the hydrogen-rich cataclysmic variables. If the accretion rate continues to fall, up to 0.1 solar masses of helium can accumulate on the more massive white dwarf. Due to the increasing pressure, the helium ignites in a final flash at the boundary layer between the C / O core and the helium. A convective energy transport forms, which leads to an ignition of the carbon in the core of the white dwarf. In contrast to the normal supernovae Ia, which occur in white dwarfs with a mass of 1.4 solar masses, the mass of the white dwarf in .Ia supernovae can only be 0.6 solar masses. The luminosity only reaches a tenth of that of normal supernovae, since there is only one deflagration . The light curve shows a steep increase in brightness and decrease which clearly differs from the normal SN Ia, while the spectral properties correspond to those of a normal SN Ia. SN 2010X has been identified as a potential supernova .Ia which shows all properties of this subgroup of thermonuclear supernovae derived from simulations. About one percent of all thermonuclear supernovae should be of the .Ia type.

literature

  • Lars Bildsten , Ken J. Shen, Nevin N. Weinberg, Gijs Nelemans: Faint Thermonuclear Supernovae from AM Canum Venaticorum Binaries . In: Astrophysical Journal Letters . tape 662 , 2007, p. L 95 , arxiv : astro-ph / 0703578 .
  • Ken J. Shen, Dan Kasen, Nevin N. Weinberg, Lars Bildsten and Evan Scannapieco: Thermonuclear .IA supernovae from Helium shell detonations: explosion models and observables . In: Astrophysical Journal . tape 715 , 2010, p. 767 , arxiv : 1002.2258v2 .
  • Mansi M. Kasliwal et al .: Rapidly Decaying Supernova 2010X: A Candidate ".Ia" Explosion . In: Astrophysical Journal Letters . tape 723 , 2010, p. L98-L102 , arxiv : 1009.0960v2 .
  • Mukremin Kilic, JJ Hermes, A. Gianninas, Warren R. Brown, Craig O. Heinke, MA Agueros, Paul Chote, Denis J. Sullivan, Keaton J. Bell, Samuel T. Harrold: Found: The Progenitors of AM CVn and Supernovae .Ia . In: Monthly Notices Royal Astron. Soc. tape 238 , 2014, p. 26 , arxiv : 1310.6359v1 .