This is mind blowing infomation.
This is an extract and the link to the the article is here Link
Supermassive black holes are millions to billions of times more massive than the sun and usually reside at the center of massive galaxies. When dormant and not feeding on the gas and stars surrounding them, SMBHs emit very little light; the only way astronomers can detect them is through their gravitational influences on stars and gas in their vicinity. However, in the early universe, when SMBHs were rapidly growing, they were actively feeding -- or accreting -- materials at intensive rates and emitting an enormous amount of radiation -- sometimes outshining the entire galaxy in which they reside, the researchers said.