Very brief radio bursts have been detected from 11 billion light years. Could these be the axial jets of black holes or collapsars? The burst may be because Earth is very briefly transiting the beam. Other possibilities?

http://phys.org/news/2013-07-cosmic-radio-cataclysmic.html

Interesting. As they observe more of them, they will learn and report more. In the mean time, we have to suffer terminal curiosity.