The Origin of Intergalactic Thermonuclear Supernovae
نویسندگان
چکیده
The population synthesis method is used to study the possibility of explaining the appreciable fraction of the intergalactic type-Ia supernovae (SN Ia), 20 −15%, observed in galaxy clusters (Gal-Yam et al. 2003) when close white dwarf binaries merge in the cores of globular clusters. In a typical globular cluster, the number of merging double white dwarfs does not exceed ∼ 10 per year per average cluster star in the entire evolution time of the cluster, which is a factor of∼ 3 higher than that in a Milky-Way-type spiral galaxy. From 5 to 30% of the merging white dwarfs are dynamically expelled from the cluster with barycenter velocities up to 150 km s. SN Ia explosions during the mergers of double white dwarfs in dense star clusters may account for∼ 1% of the total rate of thermonuclear supernovae in the central parts of galaxy clusters if the baryon mass fraction in such star clusters is ∼ 0.3%.
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