Ultra-high-energy cosmic rays from tidally-ignited stars [HEAP]


Ultra-high-energy cosmic rays (UHECRs) can be accelerated by tidal disruption events of stars by black holes. Encounters between white dwarfs with intermediate-mass black holes (IMBHs) provide a natural environment for acceleration, as tidal forces can ignite nuclear burn and lead to a supernova explosion. The numbers of IMBHs may be substantially augmented once account is taken of their likely presence in dwarf galaxies. In this Letter we show that this kind of tidal disruption event naturally provides an intermediate/heavy composition for the inferred UHECR composition. We further argue that this mechanism is virtually model-independent, as it does not rely on any specific acceleration model. Finally, we point out a possible link between ultra-luminous x-ray and UHECR sources.

Read this paper on arXiv…

R. Batista and J. Silk
Fri, 24 Feb 17

Comments: 5 pages, 1 figure