Astronomers have detected a strange radio signal that repeats every three seconds. During this three-second window, bursts of higher intensity occur every 0.2 seconds. So the signal, which takes the shape of a heartbeat, is a fast radio pulse unlike anything else. But what are these mysterious radio signals? Where are these bursts of radio waves coming from?
The mystery surrounding fast radio bursts (FRBS) began in 2007 at the Parkes Observatory in New South Wales, Australia, when astronomers were looking at radio telescope data in the hope of spotting anything unusual and mysterious. Months passed, and they found nothing. Then bang! A burst of intense radio waves for a few milliseconds, and then nothing. The tiny spike has astronomers excited. Is the signal coming from space, or is it the result of someone using a mobile phone near a radio telescope? Unfortunately, there's no way to find out, because the signal is long gone 39bet-xsmb-xổ số tây ninh-xổ số binh phước-xổ số binh dương-xổ số đồng nai. The spike was observed six years earlier in data recorded in 2001, so astronomers did what they could to detect more of these fast radio bursts.
In the process, they found 16 more spikes that resembled fast radio bursts, but they didn't seem to have much in common. If a radio burst comes from space, it will only happen at one radio pixel. That's because objects in the universe, no matter how big they are, are so far away that they appear as tiny specks in the sky. So if the burst originated in space, it would occupy only one radio pixel. But these new signals appear in all 13 of the telescope's radio pixels. Of course, it could be a radio source from Earth.
Upon examination, scientists found that it was a signal similar to a fast radio burst but originating on Earth. However, the scientists also detected four additional bursts that occupied only one radio pixel. These are fast radio bursts from space that have no connection to terrestrial radio sources. So how do scientists know? That's because, in addition to the fact that they occur at a radio pixel, the shape in front of the signal waves provides a clue that they came from space. Moreover, the interferometer puts a lower limit of 10,000 kilometers on the distance FRBS can travel, meaning they cannot have originated on Earth. However, it is not enough to know that they have a cosmic origin. So the first question that needs to be answered is, are these signals coming from inside or outside the galaxy?
The key is the signal itself. These FRBS are wideband signals, which means they have a range of frequencies. As broadband radio signals travel through gas and dust in space, lower frequency signals are delayed. So by measuring the time delay between low and high frequency signals, scientists can determine how much gas these bursts are passing through. It turns out that these signals are passing through more gas than there is in our solar system or even our own Milky Way galaxy. Thus, FRBS comes from distant galaxies.
Another clue to an extragalactic origin is that these bright punctate bursts are not concentrated in the plane of the Milky Way. Instead, they appear in the sky. But it's not enough to know that FRBS originates in distant galaxies; we need to know the exact phenomenon or object that produced the radio bursts. So astronomers built a new telescope in Australia, called ASKAP. It's an array of 36 telescopes, like a big telescope. ASKAP can not only detect fast radio bursts, but also pinpoint their origin direction to within 100,000 degrees of one degree. For example, it's about the same size as a coin 100 kilometers away. So when ASKAP found the locking direction of one of the FRBS, astronomers turned the most powerful optical telescopes, including the Hubble Space Telescope, toward the galaxy from which it came.
The fast radio burst came from a galaxy 3.5 billion light years away, meaning the radio signal we detected began its cosmic journey when life began on Earth. So how could it possibly be detected at such a great distance? Clearly, it must have been a very powerful event that caused this outbreak. This millisecond radio burst produced as much energy as our sun does in a year! Anything that produces such a millisecond long fast radio burst would be no more than 10 kilometers in diameter. And there's only one answer to how powerful the universe is, and that's a neutron star, which is the dead core of a massive star, like a giant nucleus.
Neutron stars are among the densest known objects in the universe, and even a teaspoon of the material would have a mass of 5.5 trillion kilograms, equivalent to 900 times the mass of the Great Pyramid of Giza. But neutron stars aren't the only ones emitting FRBS. Astronomers suspect they can also emerge from black hole mergers, neutron star mergers, gamma-ray bursts, supernovae. Of course, when it comes to radio signals from space, what about the assumption that many people could be generated by aliens as well?
But when astronomers discovered the first FRB from the Milky Way's interior in 2020, the case for neutron stars became even more intense. Dispersion measurements suggest the signal is coming from the direction of a galactic magnetar in the constellation Vulpecula, about 30,000 light-years away. A magnetar is a highly magnetized neutron star with a magnetic field of about a trillion terraths. This detection is an important milestone in radio astronomy, providing concrete evidence that fast radio bursts have a stellar origin.
In July 2022, astronomers detected repetitive FRBS lasting three seconds, which is about 1,000 times longer than a typical FRB. In addition, high-intensity radiation bursts occur every 0.2 seconds during a three-second window. The other strange thing about this signal is that it has mixed origin signals, and it could come from pulsars or magnets. While it's not clear how far the signal traveled, it could have come from another galaxy, and its burst appears to be more than a million times brighter than the magnetostars and pulsars in our own Milky Way galaxy. The team hopes they'll be able to catch more bursts from this mysterious source of FRB to narrow down its source and possible cause. This, in turn, could help us better understand neutron stars.