December 6, 2011 Leave a comment
Researchers have discovered two black holes larger than any we’ve ever seen before, almost 10 billion times the size of our sun, which makes them about 10,000,000,000,000,000 (10 quintillion) times the size of the Earth. As with most things cosmic or quantum, if it’s unimaginable then you’re probably thinking of it right.
From Scientific American:
The scientists used the Gemini and Keck observatories in Hawaii and the McDonald Observatory in Texas to monitor the velocities of stars orbiting around the centers of a pair of galaxies. These velocities reveal the strength of the gravitational pull on those stars, which in turn is linked with the masses of the black holes lurking there.
The new findings suggest that one galaxy, known as NGC 3842, the brightest galaxy in the Leo cluster of galaxies nearly 320 million light years distant, has a central black hole 9.7 billion solar masses large. The other, named NGC 4889, the brightest galaxy in the Coma cluster more than 335 million light years away, has a black hole of comparable or larger mass. Both encompass regions or “event horizons” about five times the distance from the sun to Pluto…
Astronomers had suspected that black holes more than 10 billion solar masses large exist, based on light from quasars, cosmic objects from the early universe that are no more than a light year or two across but are thousands of times brighter than our entire galaxy.
The light of quasars is thought to come from matter driven to incandescent brightness as it spirals at high speeds into supermassive black holes. This is the first time scientists have detected black holes approaching such theorized giants in size.
“These two new supermassive black holes are similar in mass to young quasars, and may be the missing link between quasars and the supermassive black holes we see today,” said study co-author Chung-Pei Ma, an astrophysicist at the University of California, Berkeley.
The “event horizon” mentioned is the space in which gravity is too strong for anything to escape, including light.
Quasars are regions around the center of some galaxies that glow extremely brightly; they can output far more light than an entire galaxy while being about the size of our solar system. They acquire this energy from the supermassive black holes around which they revolve, or rather from all of the matter getting pulled into and around the black holes, heating up as they go. The incredible brightness of quasars implied incredibly huge black holes, and now scientists have seen some evidence of that.
Fun fact: the largest known quasar’s black hole is estimated to consume the equivalent of 600 Earths per minute. That’s a hungry hungry black hole. Quasars were also mentioned in the news about 12 billion-year-old primordial gas clouds being discovered; the clouds were discovered because of how the light from more distant quasars passed through them. The reason quasars are particularly important in that context is because we can see them from so far away/long ago, because of their incredible brightness. It all comes back to hungry hungry black holes in the end I guess.