UNITED STATES (VOP TODAY NEWS) – Australian astronomers have doubled the number of known rapid radio burst (FRB) discovering about twenty new sources of these unexplained signals in distant galaxies. The results of their observations were published in the journal Nature.
“We still do not know in which galaxies exactly and in which parts of the universe these bursts occur. When full versions of the Square Kilometer Array (SKA) and the Australian Square Kilometer Array Pathfinder (ASKAP) are commissioned, we will be able to locate their position with accuracy up to one thousandth of a degree. This should be enough to understand where, concretely, each FRB comes from, “said Ryan Shannon, a researcher at Swinburne University of Technology in Melbourne, Australia.
The echo of the void
Astronomers first evoked the existence of mysterious radio bursts in 2007, when they were suddenly discovered during the observation of pulsars with the Australian Parkes telescope.
In the years that followed, the researchers managed to trace nine other similar bursts, the comparison of which revealed that they could have an artificial origin, or even potentially be signals of extraterrestrial civilizations because of the inexplicable periodicity of their structure.
Subsequently, astrophysicists discovered that the FRBs were repeating themselves and revealing others of their unusual peculiarities, incompatible with the main “natural” versions of their origin – which questioned these theories.
Ryan Shannon and his colleagues have doubled the number of these known signals by observing the night sky using the ASKAP construction telescope – the prototype of SKA, the world’s largest one-square kilometer radio telescope. Its construction was scheduled to begin in Australia and South Africa in 2019, and astronomers are currently developing all of its key technologies on ASKAP.
One of SKA’s main missions, says Ryan Shannon, will be looking for sources of FRB. This telescope can simultaneously observe all the night sky of the southern hemisphere of the Earth, which will allow him to find dozens of unexplained signals every day.
Its reduced version, write Australian researchers, has already found about twenty such radio anomalies in just a month and a half of observations, doubling the number of FRBs discovered over the past ten years.
For this, scientists have placed the six antennas of ASKAP, which are usually combined into a single virtual radio antenna, so that they cover an area of about 240 square degrees, a thousand times the size of the Moon in the night sky. This reduced the location accuracy of the radio signal sources, but increased the likelihood of their detection.
The new mysteries of space
According to Ryan Shannon and his colleagues, none of the twenty new FRBs were found again during repeated observations, which testifies to their unique nature. On the other hand, the study of their spectrum showed that all these bursts had appeared far beyond our galaxy, which once again excluded the theory that pulsars and other weak sources of radio waves would eventually be the “natural” origin of these signals.
The farther the source of these waves was, the more powerful were the bursts. According to the researchers, this indicates that we are far from seeing all the FRB, but only the activities of this kind sufficiently powerful.
These observations revealed another curious aspect – the frequency of occurrence of such bursts throughout the night sky of the southern hemisphere of the Earth was almost 200 times lower than predicted by the Parkes telescope observations, which monitors a particular area of the celestial sphere.
Such differences, according to Ryan Shannon, do not necessarily reflect a very disparate distribution of “mysterious signals” in the night sky. It is quite possible that they appeared because of the differences in sensitivity and the method of signal processing by the two observatories.
The completion of the ASKAP and the launch of the SKA, hope the researchers will understand the reasons for these inconsistencies and why the properties of the bursts of a single repeated source, the object FRB 121102 in the constellation of Check, differ significantly from the characteristics of the unique “mysterious signals”.