KnowraUltra-high-energy cosmic rayLinked fromLinked fromThe 5 pages that link to Ultra-high-energy cosmic ray, each with the reason it gives.All 5Broader topic 2Related 3BlazarRelated: Blazar jets are candidates for accelerating particles to these extreme energies.Centaurus ARelated: Centaurus A has been considered a possible source because of its proximity and powerful jets.Markarian 501Related: Whether blazar jets such as Markarian 501 accelerate these particles remains an open question.