Most distant blazar is a high-energy astrophysics puzzle
Thursday, April 18, 2013 - 11:56
in Astronomy & Space
(Phys.org) —Blazars are the brightest of active galactic nuclei, and many emit very high-energy gamma rays. New observations of the blazar known as PKS 1424+240 show that it is the most distant known source of very high-energy gamma rays, but its emission spectrum now appears highly unusual in light of the new data.