Sat. Oct 16th, 2021


Radio signals emanating from the galactic center.

By 2020, Australian astronomers have discovered a mysterious radio wave coming from somewhere near the center of the galaxy. But when the team trained more sensitive instruments toward the source, they saw it once more before it disappeared, behaving differently than before. The signal is described in a paper Published Today in the Astrophysical Journal.

“The strangest feature of this new signal is that it has a very high polarization. This means that its light only swings in one direction, but that direction rotates over time,” said Jiteng Wang, an astronomer at the University of Sydney and lead author of the new study. Press release. In other words, radio waves were occasionally crashing into the earth without any rhyme or reason. And since they have been identified, the path has become cold.

The signal was invented using Australian square kilometer array pathfinder variables and slow transients (ASKAP VAST) Survey, a radio telescope based in far-western Australia. The mystery object that made the signal was named ASKAP J173608.2-321635, for the telescope that found it and its coordinates in the sky.

“This object was so unique that it started invisibly, became brighter, faded, and then reappeared. The behavior was remarkable, ”said Tara Murphy, an astronomer and co-author of the research paper at the University of Sydney in the same release.

When the radio source goes dark, the team examines the spectrum of visible light, finding nothing. They also became a Various radio telescopes, Which generates nothing of a similar amount. But then, using the Meerkat radio telescope in South Africa, the team finally got to see the object again, but it disappeared within a day. Researchers have not seen it since.

Galaxy.

As seen in the Milky Way from Uruguay. The radio source came from the Galactic Center.
Pictures: Mariana Suarez / AFP (Getty Images)

“Why a source would stop emissions could be something related to instability in the magnetic field. Magnetic fields can get involved and then release energy into explosions,” said David Cap, an astronomer and co-author of the study, in an email to Gizmodo. “It happens to our sun, magnets and other kinds of objects. So it’s not so much that it stops emission, because it only emits sporadically (most of the time it stays off).

Researchers have some ideas about what radio sources might be, but they’re not sure which ones. The radio wave pattern is similar to that of a class of objects called galactic center radio transients, although there are some differences. Galactic center radio transients are not a specific object but a group of radio-emitting objects around the galaxy center that do not have a specific identity.

Due Features of its explosion, the team first thought of it ASKAP can be J173608.2-321635 A pulsar – a revolving dead star Whose brightness changes regularly to observers around the world. But the luminosity fluctuations of this object were not regular, and the lack of other electromagnetic waves meant that it was not like a small brown dwarf star or a high magnetic magnet. Kaplan said it could be an “odd” pulsar, but the team wouldn’t know for sure with their current data.

EIf ASKAP J173608.2-321635 is not seen again, they hope that future observations will determine whether the object was a rule or an exception অর্থাৎ that is, whether the source is the first of an unaltered class of objects. Or something else.

IInstead of lipfragging from radio telescopes to radio telescopes in the future, the team hopes to use Square kilometer array, The world’s largest radio telescope With 130,000 antennas for remote monitoring of remote radio sources. Regular science observations towards the array are expected to begin This is the end Decade

More: The New South African Telescope has released an epic image of the Galactic Center



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