4 billion times the sun! The Most Intense Optical Ultraviolet Radiance in the Universe Appears International | UV Light | Sun
On the 27th, the Zijinshan Astronomical Observatory of the Chinese Academy of Sciences announced that an international team led by researchers Fan Yizhong and Jin Zhiping of the observatory had discovered the most intense optical ultraviolet radiation ever detected by humans with the Swift Satellite UV Optical Telescope. The research findings were published online on June 26th in the international academic journal Nature Astronomy.
Gamma ray bursts, abbreviated as gamma bursts, are the most intense stellar scale explosions in the universe, with the main radiation energy concentrated in the soft gamma ray band. Therefore, soft gamma radiation is also known as the instantaneous radiation of gamma bursts. After the instantaneous radiation ends, people can often observe X-ray radiation, optical radiation, and even radio radiation that lasts for several weeks or even years, which is commonly known as afterglow radiation.
On January 1, 2022, the Swift satellite detected a new gamma storm GRB 220101A. Due to its bright optical afterglow, scientists quickly measured its redshift value to be 4.618.
"But the detected optical radiation is actually red shifted ultraviolet photons. The absorption effect of these ultraviolet photons is very serious, and they have lost about 99% before reaching the earth, that is, the actual radiation flow is about 100 times the observed value. This shows that GRB 220101A is an extremely intense optical ultraviolet radiation." Fan Yizhong, the corresponding author of the paper and a researcher at the Zijinshan Observatory of the Chinese Academy of Sciences, said that the researchers found in the subsequent analysis that the absolute magnitude of GRB 220101A reached -39.4, which is the only optical ultraviolet radiation source with an absolute pair of stars brighter than -39.
"The ultraviolet optical radiance of GRB 220101A is about 4 billion times that of the Sun, breaking the world record held by GRB 080319B for 14 years," said Fan Yizhong.
In January 1999, an optical telescope in the United States detected the gamma storm GRB 990123. At the end of the instantaneous radiation of GRB 990123, people saw bright optical shining phenomena. Fan Yizhong said that at that time, the optical flare was the most luminous ultraviolet optical radiation recorded by humans in the universe, and its radiation region had a strong magnetic field.
In 2008, humans recorded the instantaneous optical radiation of GRB 080319B. For a long time, GRB 080319B has held the world record for the most intense optical ultraviolet burst event in the universe.
Fan Yizhong introduced that this study found that the optical radiation behavior of GRB 220101A is not only different from the optical ultraviolet flare of GRB 990123, which marks the beginning of afterglow, but also different from the GRB 080319B, which directly tracks the activity of the central engine, indicating that the physical origin of ultra bright optical ultraviolet bursts is diverse.