Era of first fast growth of the most massive black holes determined
By ANITuesday, December 28, 2010
WASHINGTON - Scientists from the Tel Aviv University have determined that the era of first fast growth of the most massive black holes occurred when the universe was only about 1.2 billion years old - not two to four billion years old as popularly thought.
Prof. Hagai Hetzer and his research student Benny Trakhtenbrot have conducted the research based on observations from Gemini North on top of Mauna Kea in Hawaii, and the Very Large Telescope array on Cerro Paranal in Chile.
Results show that the black holes that were active when the universe was 1.2 billion years old are about 10 times smaller than the most massive black holes that are seen at later times. However, they are growing much faster.
They found that the very first black holes - the ones that started the entire growth process when the universe was only several hundred million years old - had masses of only 100 to 1000 times the mass of the Sun.
Such black holes may be related to the very first stars in the universe. They also found that the subsequent growth period of the observed sources, after the first 1.2 billion years, lasted only 100 to 200 million years.
The study will be published in the Astrophysics Journal. (ANI)
