قالب وردپرس درنا توس
Home / Science / Astronomers discover the source of unexplained cosmic radio bursts

Astronomers discover the source of unexplained cosmic radio bursts



  Smaller Fast Radio Burst

To discover the source of a unique, mysterious space signal, an international team of astronomers used telescopes around the world.


CSIRO / Dr. med. Andrew Howells

Astronomers keep hearing unexplained, incredibly powerful signals from the distance of space – signals that come through a thousandth of a second loud and clear and then mysteriously disappear. First discovered in 2007, "these pulses are known as fast radio bursts," and they remain one of the universe's greatest secrets. Dozens of enigmatic cosmic signals have been discovered, and astronomers have spent the past decade thinking about where they come from and what causes them.

In an historic premiere, an international research team identified the location of a non-repeating rapid radio burst and found that its source is at the edge of a galaxy 4 billion light-years away.

The monumental results, published Thursday in the AAAS journal Science, describe the discovery and localization of FRB 180924, a powerful, one-time, fast radio burst that lasted only a fraction of a second. Speculation about the cause of the bizarre signals ranges from explosive neutron stars to alien spaceships, and although we are still not sure what causes them, the discovery brings astronomers one step closer to their true nature. A great breakthrough to the field has been waiting since astronomers discovered rapid bursts of radioactivity in 2007, "said Keith Bannister, principal author of the paper and Chief Research Engineer of the Australian Commonwealth Scientific and Industrial Research Organization.





  http://www.cnet.com/


Now in the works: [19659009] Look at this:

Aliens and the Search for Extraterrestrial Intelligence





6:23

The eruption was picked up by the Australian Pathfinder square kilometer array, which consists of 36 radio telescopes working together to search the sky and search for radio signals. ASKAP is located in the Australian outback, where there is little interference, and is able to pick up the quietest whisper in the universe. The burst came from the other side of the universe and hit ASKAP's array – and within half a second the machine stopped searching and downloaded the data from each of the 36 courts.

The breakout hits every dish at slightly different times. In a ridiculous technical performance, the team can calculate the difference in arrival time to a tenth of a nanosecond. So her detective work can begin by tracking her position to a point in the sky – essentially plucking a needle from a haystack.

The research team found that FRB 180924 came from a distant galaxy whose size is very similar to our own Milky Way galaxy. Galaxies are huge, swirling stellar masses, but the team could make out the exact cosmic city block of the eruption, about 13,000 light-years from the center of the galaxy.

  Aerial 29's view of the Australian square kilometer Array Pathfinder while waiting for deep-space signals.

The view from antenna 29 on the Australian square kilometer array Pathfinder, which listens to deep-space signals.


CSIRO / Alex Cherney

After locating the outbreak, the research team used a number of other telescopes around the world, including the Very Large Telescope and the Gemini South Telescope in Chile, and the Keck Telescope in Hawaii. When these extra-cosmic eyes were trained on-site, the team was able to further characterize the place.

Only once, in 2017, was a rapid radio burst attributed to its source – and the one particular investigation was somewhat simpler as the eruption at times repeated itself, such as a flash. Known as FRB 121102 or the "Repeater", the breakout came from a very different source than FRB180924: a dwarf galaxy just over 3 billion light-years away.

"The outburst we have located and its host galaxy are not similar to the 'repeater' and its host," said Adam Deller, astrophysicist at Swinburne University of Technology.

This indicates that non-repeating fast radio bursts may be different from those that repeat, or that the signal differs depending on where it comes from.

"The evidence certainly indicates that FRBs live in a variety of environments, so it's not surprising that their bursting properties, whether or not they repeat themselves, also vary widely," said Bannister , [19659006] It is one thing to locate the signal, but it is so far from Earth that we can not possibly see exactly what it is causing. For ASKAP this is just the beginning. Bannister notes that the group is "almost fully armed and operational" and expects to locate more bursts in the future.

"We are constantly expanding the capabilities of telescopes and are better at finding the needles in a haystack," adds Deller.

With all sorts of fantastic explanations for the rare cosmic signals – magnetars neutron stars and aliens – Bannister does not rule out extraterrestrial intelligence.

"I think it's very likely that we will find a natural explanation for these events, but I like to be open minded and follow where the evidence leads me."

Updated at 15:15 PT: Additional comments added by researchers


Source link