Enthusiastic example Gamma ray burstThe most powerful types of explosions known in space suggest that these explosions do not always work as scientists thought, and versions of these flares can be surprisingly short. Researchers say.
A typical gamma-ray burst emits more energy in a few milliseconds to a few minutes. Sun It is expected to be emitted over the entire 10 billion year life. Astronomers classify gamma-ray bursts into long and short bursts based on whether the explosion lasts more than 2 seconds or less than 2 seconds.Previous studies have suggested that short gamma-ray bursts result from the merger of the two. Neutron star, This is a very dense stellar corpse formed by the collapse of a giant star. In contrast, astronomers have long gamma-ray bursts, Supernova, The result of the explosion of a giant star.
Scientists have now discovered short gamma-ray bursts formed in the same way that long gamma-ray bursts are usually thought of from the collapse of a single giant star. Thomas Ahmada, a PhD student in astronomical physics at the University of Maryland and NASA’s Goddard Space Flight Center in Maryland, and lead author of research on newly discovered gamma-ray burst afterglow, said, “Dying. Stars also produce very short gamma-ray bursts. ” .com.
Scientists have focused on gamma-ray bursts called GRB200826A that occurred in a galaxy about 6.6 billion light-years away in Andromeda. The explosion lasted only 0.65 seconds, but after decades of traveling through the expanding universe, this signal stretched to about 1 second when detected by NASA on August 26, 2020. .. Fermi Gamma-ray Space Telescope..
Other spacecraft have also found bursts. NASA’s wind missions orbit about 930,000 miles (1.5 million kilometers) between the Earth and the Sun. NASA Martian Martian, Has been orbiting the red planet since 2001. And the INTEGRAL satellite of the European Space Agency launched in 2002.
When astronomers saw gamma-ray bursts and decided to follow up on the event, they were hoping to find signs of collision between the two neutron stars. But that’s not what scientists have seen at all.
Scientists used Hawaii’s 8.1-meter Gemini North telescope to analyze gamma-ray burst host galaxies 28, 45, and 80 days after the explosion was first detected last summer. These observations revealed that after the afterglow of the burst disappeared, it brightened again. This rise in energy came from a supernova that occurred after the explosion that caused the gamma-ray burst itself.
“It was very difficult to analyze the data and images because we had to separate the light of the supernova from the light of its host galaxy,” Ahmada said.
This discovery was “especially surprising because it wasn’t really what we were looking for,” Ahmada explained.He and his colleagues are analyzing data from Astronomical Survey Facility “To look for binary neutron star mergers that are thought to produce short gamma-ray bursts” at the Palomar Observatory in California.
Instead, scientists have discovered the aftermath that would be expected from an explosion following the collapse of a giant star. “I found a dead star,” Ahmada said.
According to Nanjing University’s Bin-bin Zhang, scientists have long known that some gamma-ray bursts from exploding stars can appear as short gamma-ray bursts, but astronomers have said this. We attributed this to the limitations of the equipment used to detect such events. Lead author of research on gamma-ray data at the University of Nevada, Las Vegas, China. “This burst is arguably a short gamma-ray burst, so it’s special, but other properties indicate its origin from a collapsing star,” Zhang said. NASA Statement..
Last year’s detection was the shortest known gamma-ray burst powered by the death of an implosion star. Researchers have found that gamma-ray bursts erupting from the poles of a collapsing star are not strong enough to completely break through the outer envelope of the star, which makes it and other supernova-driven gamma-ray bursts appear short. Suggests. Most other collapsing stars have such weak jets, they produce no detectable gamma-ray bursts.
“I think this event was a mess that virtually never happened,” Ahmada said in a statement. “Still, the burst released 14 million times the energy emitted from the whole. Milky Way A galaxy of the same time, one of the most energetic short-term gamma-ray bursts ever seen. “
This discovery may help solve a long-standing mystery. Previous studies have associated long gamma-ray bursts with supernovae, but astronomers have detected far more supernovae than long gamma-ray bursts. The discovery of short gamma-ray bursts associated with supernovae suggests that some supernova-driven gamma-ray bursts may be spoofing short gamma-ray bursts previously thought to have been created by neutron star mergers. increase. A type of supernova.
Finding such shorter gamma-ray bursts in the future may help explore the various precursors of these explosions, “because we are not entirely sure how this event was generated.” Ahmada said.
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Astronomers capture incomplete gamma-ray bursts from supernovae
Source link Astronomers capture incomplete gamma-ray bursts from supernovae