Blazars are compact objects that emit high-energy bursts of radiation. During the last few years, astronomers have used data collected from the satellite Fermi, designed to detect these bursts, to study blazar radiation, helping astronomers better understand these objects. This article describes some new results of how radiation from a blazar interacts with material that surrounds it. 

http://www.raa-journal.org/raa/index.php/raa/article/view/719