A team of astronomers from the University of California, Berkeley, led by Taiwanese astrophysicist Ma Chung-pei (馬中珮), have found the largest black holes ever discovered — each 10 billion times more massive than our sun.
The discovery of the two black holes, at the centers of two galaxies more than 300 million light years from Earth, will be published by Ma and co-author Nicholas McConnell, a US graduate student researcher at Berkeley.
These black holes are so large that their “event horizons” — the area within which nothing can escape their gravitational pull, not even light — are seven times greater than the size of our solar system, the Times reported on Saturday.
“They are monstrous,” Ma told reporters. “We did not expect to find such massive black holes because they are more massive than indicated by their galaxy properties. They’re kind of extraordinary.”
She said research done in the past showed that the bigger the galaxy, the bigger the black hole.
Using telescopes at the Gemini and Keck observatories in Hawaii and at McDonald Observatory in Texas, Ma and McConnell obtained detailed spectra of the diffuse -starlight at the centers of several massive elliptical galaxies. Each one is the brightest galaxy in its cluster, lying about 270 million light years from Earth, they found.
So far, they have analyzed the orbital velocities of stars in two galaxies and calculated the central masses to be in the range of young quasars. The scientists suggest these black holes might be the leftovers of quasars that crammed the early universe
“For an astronomer, finding these insatiable black holes is like finally encountering people nine feet tall whose great height had only been inferred from fossilized bones. How did they grow so large?” Ma said in a news release.
“This rare find will help us understand whether these black holes had very tall parents or ate a lot of spinach,” she said.
“Through this finding, we’ve also concluded that these massive black holes are at the center of the Milky Way Galaxy,” Ma added.
“If there are any bigger black holes, we should be able to find them in the next year or two,” she said. “I think we are probably reaching the high end now.”
Ma, a theoretical astrophysicist, is also on an overseas academic advisory panel of the Academia Sinica Institute of Astronomy and Astrophysics in Taipei. Her father, Ma Chi-shen (馬驥伸), is a veteran journalist and her mother, Huang Chao-heng (黃肇珩), is a former member of the Control Yuan.
The scientific report on the two black holes is set to be published in tomorrow’s issue of the British journal Nature.
Additional reporting by AP