You may be referencing two different kind of radiations:
- the one emitted by the heated matter falling in / spinning around the black hole (the quasar referenced in the article [1])
- the Hawking radiation. Basically a pair of particle/antiparticle randomly appears near the black hole event horizon, one of the particle falls into the black hole while the other one escapes. The black hole would eventually evaporate if you waited long enough. [2]
- the one emitted by the heated matter falling in / spinning around the black hole (the quasar referenced in the article [1])
- the Hawking radiation. Basically a pair of particle/antiparticle randomly appears near the black hole event horizon, one of the particle falls into the black hole while the other one escapes. The black hole would eventually evaporate if you waited long enough. [2]
[1] http://en.wikipedia.org/wiki/Quasar [2] http://en.wikipedia.org/wiki/Hawking_radiation