Astronomers Identify 'Missing Link' Mid-Sized Black Hole
2020-04-14
LRC
TXT
大字
小字
滚动
全页
1Scientists have identified a mid-sized black hole that could be the "missing link" to help us better understand these mysterious space objects.
2Researchers used data from NASA's Hubble Space Telescope and two X-ray observatories to find the black hole, which was in the process of destroying a nearby star.
3Black holes are extremely dense objects possessing gravitational pulls so powerful that not even light can escape.
4The newly identified black hole is more than 50,000 times the mass of our sun.
5It sits about 740 million light years from Earth in a galaxy containing far fewer stars than our Milky Way.
6A light year is the distance light travels in a year, about 9.5 trillion kilometers.
7This is one of the few "intermediate-mass" black holes ever identified.
8It is far smaller than the supermassive black holes found at the center of large galaxies.
9But, it is much larger than so-called stellar-mass black holes formed by the collapse of huge individual stars.
10Natalie Webb is an astrophysicist at the University of Toulouse in France.
11She helped lead a study on the black hole that was recently reported in the publication Astrophysical Journal Letters.
12Webb told the Reuters news agency the study confirmed that the object her team first discovered back in 2010 was in fact an intermediate-mass black hole.
13The star it was destroying was probably about a third the mass of our sun.
14Webb noted that scientists have searched for intermediate-mass black holes for more than 40 years.
15However, fewer than 10 good examples are known.
16Scientists believe large numbers of the objects may exist even though they have not been discovered.
17"So finding a new one is very significant. Also, a black hole swallowing a star happens on average only once every 10,000 years or so in any ... galaxy so these are rare occurrences," Webb added.
18The supermassive black hole at the center of the Milky Way is 4 million times the mass of the sun, about 26,000 light years from Earth.
19The closest stellar-mass black star is about 6,000 light years from Earth.
20Webb called intermediate black holes the "missing link" in understanding the range of black holes.
21Scientists know a lot about the formation of stellar-mass black holes, which are about three to 100 times the mass of our sun.
22But they do not know how intermediate-mass black holes form.
23Scientists do have a theory that supermassive black holes arise from mid-size ones.
24However, Webb noted that "without finding such objects, it was impossible to validate this theory."
25Intermediate-mass black holes remain difficult to find and scientists are not exactly sure why.
26But University of New Hampshire astronomer and lead researcher Dacheng Lin does offer one idea.
27"The best explanation is that they are mostly in an environment that is devoid of gas, leaving the black holes with no material to consume and ... little radiation to emit - which in turn makes them extremely difficult to spot," he said.
28I'm Pete Musto.
1Scientists have identified a mid-sized black hole that could be the "missing link" to help us better understand these mysterious space objects. 2Researchers used data from NASA's Hubble Space Telescope and two X-ray observatories to find the black hole, which was in the process of destroying a nearby star. 3Black holes are extremely dense objects possessing gravitational pulls so powerful that not even light can escape. 4The newly identified black hole is more than 50,000 times the mass of our sun. It sits about 740 million light years from Earth in a galaxy containing far fewer stars than our Milky Way. A light year is the distance light travels in a year, about 9.5 trillion kilometers. 5This is one of the few "intermediate-mass" black holes ever identified. It is far smaller than the supermassive black holes found at the center of large galaxies. But, it is much larger than so-called stellar-mass black holes formed by the collapse of huge individual stars. 6Natalie Webb is an astrophysicist at the University of Toulouse in France. She helped lead a study on the black hole that was recently reported in the publication Astrophysical Journal Letters. 7Webb told the Reuters news agency the study confirmed that the object her team first discovered back in 2010 was in fact an intermediate-mass black hole. The star it was destroying was probably about a third the mass of our sun. 8Webb noted that scientists have searched for intermediate-mass black holes for more than 40 years. However, fewer than 10 good examples are known. Scientists believe large numbers of the objects may exist even though they have not been discovered. 9"So finding a new one is very significant. Also, a black hole swallowing a star happens on average only once every 10,000 years or so in any ... galaxy so these are rare occurrences," Webb added. 10The supermassive black hole at the center of the Milky Way is 4 million times the mass of the sun, about 26,000 light years from Earth. The closest stellar-mass black star is about 6,000 light years from Earth. 11Webb called intermediate black holes the "missing link" in understanding the range of black holes. Scientists know a lot about the formation of stellar-mass black holes, which are about three to 100 times the mass of our sun. But they do not know how intermediate-mass black holes form. 12Scientists do have a theory that supermassive black holes arise from mid-size ones. However, Webb noted that "without finding such objects, it was impossible to validate this theory." 13Intermediate-mass black holes remain difficult to find and scientists are not exactly sure why. 14But University of New Hampshire astronomer and lead researcher Dacheng Lin does offer one idea. "The best explanation is that they are mostly in an environment that is devoid of gas, leaving the black holes with no material to consume and ... little radiation to emit - which in turn makes them extremely difficult to spot," he said. 15I'm Pete Musto. 16Will Dunham reported on this story the Reuters news agency. Pete Musto adapted it for VOA Learning English. Bryan Lynn was the editor. We want to hear from you. Write to us in the Comments Section. 17_______________________________________________________________ 18Words in This Story 19intermediate - adj. occurring in the middle of a process or series 20significant - adj. very important 21occurrence(s) - n. something that happens 22range - n. a group or collection of different things or people that are usually similar in some way 23validate - v. to show that something is real or correct 24devoid of - adj. completely without something 25consume - v. to use fuel, time, or resources 26emit - v. to send light, sound or energy out from a source