“We have never seen anything like it”: they detect rare radio signals in the center of the Milky Way

Astronomers have discovered unusual signals coming from the center of the Milky Way. These are radio waves that do not conform to any currently understood variable radio source pattern and could suggest a new class of stellar object, as published in the Astrophysical Journal.

“The strangest property of this new signal is that it has a very high polarization. This means that your light oscillates in only one direction, but that direction rotates over time –explains Ziteng Wang, lead author of the new study and a doctoral student at the School of Physics at the University of Sydney in Australia-., by a factor of 100, and the signal turns on and off seemingly randomly. We have never seen anything like it “, admits.

Many types of stars emit variable light throughout the electromagnetic spectrum. With the enormous advances in radio astronomy, the study of variable or transient objects in radio waves is a huge field of study that helps us reveal the secrets of the universe. Fast p’s are all kinds of astronomical objects whose brightness varies.

The galaxy’s center of rotation is home to a large black hole at its center, and in the region are huge dense clusters of stars including red giants, super giants, extremely hot gases, and f

“At first we thought it might be a pulsar –a very dense dead star type that rotates– or a type of star that emits huge solar flares. But the signals from this new source do not coincide with what we expect from this type of celestial object ”, remember.

Wang and an international team of scientists from the Australian national scientific agency CSIRO, Germany, the United States, Canada, South Africa, Spain and France, discovered the object using the CSIRO ASKAP radio telescope in Western Australia. Subsequent observations were made with the MeerKAT telescope of the South African Radio Astronomical Observatory.

Wang’s PhD supervisor, Professor Tara Murphy, also from the Sydney Institute of Astronomy and the College of Physics, explains that they have been surveying the sky with ASKAP for a project known as Variables and Slow Transients (VAST), a throughout 2020 and 2021.

“Looking towards the center of the Galaxy, we find ASKAP J173608.2-321635, named for its coordinates –aim-. This item was unique in that, it became bright, faded, and then reappeared. This behavior was extraordinary ”.

After detecting six radio signals from the source over nine months in 2020, astronomers tried to find the object in visual light, but found nothing. They then resorted to the Parkes radio telescope but again failed to detect the source.

Murphy explains that they next tested the more sensitive MeerKAT radio telescope in South Africa. “Since the signal was intermittent, we watched it for 15 minutes every few weeks, hoping to see it again –remember-. Luckily, the signal came back, but we found out that: the source disappeared in a single day, although it had lasted for weeks in our previous observations of ASKAP ”.

However, this new discovery did not reveal much more about the secrets of this transient radio source.

Wang’s co-supervisor, Professor David Kaplan of the University of Wisconsin-Milwaukee, notes that “The information obtained has some parallels with another emerging class of mysterious objects known as Radio Transients of the Galactic Center, including one dubbed the

“Although our new object, ASKAP J173608.2-321635, shares some properties with GCRTs, there are also differences –points out-. And anyway, so this adds to the mystery. “

The scientists plan to closely follow the object to look for more clues as to what it could be. “In the next decade, the Square Kilometer Array (SKA) transcontinental radio telescope will become operational. You will be able to make sensitive maps of the sky every day ”, notes Professor Murphy.

“We hope that the power of this telescope will help us solve mysteries like this latest discovery, but it will also open vast new swaths of the cosmos to exploration on the radio spectrum.”, concludes.

Agency

Follow us on twitter: