Doubt cast on source of universe’s mightiest particles
May 14, 2008 | Source: NewScientist.com news service
Stanford University researchers have found that black holes in nearby galaxies are not a likely source of ultra-high-energy cosmic rays (UHECR).
Instead, UHECRs are more likely to come from the more energetic breeds of an active galaxy, such as quasars and radio galaxies.