•   
  •   
  •   

Technology Milky Way core may harbour thousands of black holes: study

20:10  05 april  2018
20:10  05 april  2018 Source:   afp.com

Supermassive Black Holes Grow Faster In Larger Galaxies

  Supermassive Black Holes Grow Faster In Larger Galaxies The rate of growth of the biggest supermassive black holes in the universe is much faster than the rate at which new stars are born in the massive galaxies that host them.When it came to growth, it was thought that supermassive black holes that lie at the centers of most galaxies accumulated mass at roughly the same pace at which new stars were being born in those galaxies. But two new studies have shown that the largest supermassive black holes (with masses billions of times the sun) which reside in some of the most massive galaxies in the universe grow much faster than the rate at which those galaxies form new stars.

Astrophysicists have detected a dozen black holes at the centre of our Milky Way galaxy, and said Wednesday there could be as many as 10,000. The find provides the first evidence for a long-held theory that the massive black hole at the core of every large galaxy should be surrounded by

Paris: Astrophysicists have detected a dozen black holes at the centre of our Milky Way galaxy, and said Wednesday there could be as many as 10,000. The find provides the first evidence for a long-held theory that the massive black hole at the core of every large galaxy should be surrounded by

In total, the Milky Way is about 100,000 light years wide © Provided by AFP In total, the Milky Way is about 100,000 light years wide Astrophysicists have detected a dozen black holes at the centre of our Milky Way galaxy, and said Wednesday there could be as many as 10,000.

The find provides the first evidence for a long-held theory that the massive black hole at the core of every large galaxy should be surrounded by thousands of smaller ones, they wrote in the science journal Nature.

"We observed a dozen black holes" around Sagittarius A, the black hole at the centre of the Milky Way, said study co-author Chuck Hailey, an astrophysicist at New York's Columbia University.

Most Massive Black Holes in the Universe Detected

  Most Massive Black Holes in the Universe Detected More than half of these "ultramassive" black holes have a mass 10 billion times greater than that of the Sun.The “ultra-massive” black holes are located up to 3.5 billion light years from Earth. They were spotted using data captured by NASA’s Chandra X-ray telescope, a space observatory that has greatly advanced the field of X-ray astronomy.

PARIS - Astrophysicists have detected a dozen black holes at the centre of our Milky Way galaxy, and said Wednesday there could be as many as 10,000. The find provides the first evidence for a long-held theory that the massive black hole at the core of every large galaxy should be surrounded by

Astrophysicists have detected a dozen black holes at the centre of our Milky Way galaxy, and said Wednesday there could be as many as 10,000. The find provides the first evidence for a long-held theory that the massive black hole at the core of every large galaxy should be surrounded by

"But this is the tip of the iceberg," he told AFP.

Black holes are generally "pretty impossible" to see, according to the physicist.

They feast on gas and dust in their vicinity, but the X-rays they burp are sporadic and hard to observe from Earth.

To try and overcome this difficulty, Hailey and a team decided to track down black hole "binaries" -- duos occasionally formed when a black hole captures a passing star and binds to it.

When the captured star has a low mass, the binary emits X-ray bursts that are weak but consistent and easier to detect.

The team observed the X-ray signatures of 12 black hole binaries within three light years of Sagittarius A.

'Tons of black holes'

Based on data from studying black holes closer to Earth, they extrapolated there must be about 500 binaries around our galaxy's core in all, most of them too dim to observe.

New Results Challenge Basic Ideas of Supermassive Black Holes

  New Results Challenge Basic Ideas of Supermassive Black Holes Galaxies have supermassive black holes at their centers—our Milky Way, for example, has its own 4-million-solar-mass one, Sagittarius A*. Galaxies have supermassive black holes at their centers—our Milky Way, for example, has its own 4-million-solar-mass one, Sagittarius A*. Some astronomers have previously thought that there’s a simple relationship between the galaxy’s size, the black hole’s mass, and how much light the black hole spits out while it eats up the things surrounding it. But a pair of papers studying the biggest star-eating behemoths imaginable seems to bust up that assumption.

Astrophysicists have detected a dozen black holes at the centre of our Milky Way galaxy, and said Wednesday there could be as many as 10,000. The find provides the first evidence for a long-held theory that the massive black hole at the core of every large galaxy should be surrounded by

PARIS - Astrophysicists have detected a dozen black holes at the center of our Milky Way galaxy, and said Wednesday there could be as many as 10,000. The find provides the first evidence for a long-held theory that the massive black hole at the core of every large galaxy should be surrounded by

"The final step comes from theorists, who estimate that only about one in 20 isolated black holes will eventually find a companion star" to form a binary, Hailey explained.

"So, multiplying by 20, we get around 10,000 isolated black holes" around Sagittarius A, he added.

Scientists had previously identified five dozen black holes in the rest of the galaxy, further from the centre.

In total, the Milky Way is about 100,000 light years wide.

The biggest black holes have masses ranging from millions to billions of times that of the Sun.

"Our galaxy is quite normal, so if you see tons of black holes here, they must exist in the centres of most galaxies," said Hailey.

"We had no evidence for bunches of black holes before, and our estimates, based on the dozen we see, are consistent with our expectations. This is gratifying," he added.

Our galaxy's colossal black hole may have huge hidden 'siblings' .
New research shows the Milky Way and galaxies like it may contain several supermassive black holes.Now the results of a large-scale cosmological simulation are in, and they suggest that galaxies like ours commonly host several of these supermassive black holes (SMBHs) — including some that wander unseen far from the galaxies' centers.

—   Share news in the SOC. Networks

Topical videos:

usr: 1
This is interesting!