2021-10-13

Strange radio signals from the center of the galaxy excited scientists

By yqqlm yqqlm

“The brightness of the object also changes greatly. The difference between light and dark can be 100 times, and the opening and closing of the signal is obviously random. We have never seen such a thing.”

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the main author is Ziteng Wang, a doctoral student at the University of Sydney

many types of stars emit variable light in the whole electromagnetic spectrum. With the great progress of radio astronomy, the research on variable or transient objects in radio waves is a huge research field, which can help us reveal the secrets of the universe. Pulsars, supernovae, twinkling stars and fast radio storms are all types of astronomical objects with varying brightness

“at first we thought it might be a pulsar — a very dense rotating Death Star — or a star that emits huge solar flares. But the signals from this new source are inconsistent with our expectations of these types of objects,” Mr. Wang said. The discovery of the celestial body was published in the Journal of astrophysics today (October 12, 2021)

Strange radio signals from the center of the galaxy excited scientists

co author Professor Tara Murphy, Institute of astronomy, University of Sydney

Wang and an international team, including scientists from CSIRO, the national scientific institution of Australia, Germany, the United States, Canada, South Africa, Spain and France, discovered the object using CSIRO’s askap radio telescope in Western Australia. Subsequent observations were made through the meerkat telescope of the South African Radio Observatory

Mr. Wang’s doctoral supervisor is Professor Tara Murphy, also from the Institute of astronomy and the school of physics in Sydney. She said: “throughout 2020 and 2021, we have been surveying the sky with askap to find unusual new objects. This project is called variable and slow transient (VAT) Looking at the center of the Milky Way galaxy, we found askap j173608.2-321635, named after its coordinates. The uniqueness of this celestial body is that it is invisible at first, becomes bright, gradually disappears, and then reappears. This behavior is unusual

Strange radio signals from the center of the galaxy excited scientists(1)

Strange radio signals from the center of the galaxy excited scientists(2)

artist’s impression of the oscillation and variable radio signal askap j173608.2-321635 from the center of the Milky Way galaxy to the earth

in the nine months of 2020, after detecting six radio signals from the signal source, astronomers tried to find the object in visual light. They got nothing. They turned to the parks radio telescope and failed to detect the source

Professor Murphy said. “Then we tried the more sensitive meerkat radio telescope in South Africa. Because the signal was intermittent, we observed it for 15 minutes every few weeks, hoping to see it again. Fortunately, the signal came back, but we found that the behavior of the signal source was very different – the signal source disappeared in a day, although it lasted several years in our previous askap observation Weeks. ”

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however, this further discovery does not reveal more secrets about this instantaneous radio source

co tutor, Professor David Kaplan from the University of Wisconsin Milwaukee. “The information we have has some similarities with another new kind of mysterious objects. These objects are called galactic Central Radio transistors, including an object called’Cosmic explosive’. Although the new object we found, askap j173608.2-321635, does have some common properties with gcrts, it also has some differences. Moreover, in any case, we do not know Really understand these sources, so it increases the sense of mystery. ”

scientists plan to pay close attention to this object to find more clues to what it may be

“in the next decade, the transcontinental square kilometer array (ska) radio telescope will be online. It will be able to produce sensitive sky maps every day,” said Professor Tara Murphy. “We hope that the power of this telescope will help us solve puzzles such as this latest discovery, but it will also open up broad new areas for exploring the universe in the radio spectrum.”