Friday, April 18, 2008
A quasar is a supermassive black hole (see here, here, here and here) at the center of a young galaxy. The farthest are 28 billion light-years away, making them that most distant objects ever observed. They are so far that the energy they emit to make them visible most be equivalent to over 100 galaxies or a trillion suns. Over 100,000 quasars have been detected with more on the way. Some quasars can even be viewed with a small telescope, due to their luminosity with equals around 2 trillion suns. An average quasar absorbs 10 solar masses (10 times the sun's mass) each year. The biggest consumption on record being 1000 solar masses per year or 600 Earths per hour! No quasars are in our supercluster because once they absorb all the mass in their proximity, they die out and become ordinary black holes, leaving a regular galaxy behind. Quasars are that most powerful objects in our known Universe.