An article published in the journal “Nature” reports the results of a survey on Fast Radio Bursts (FRBs), intense radio emissions from other galaxies. A team of researchers used the Australia Square Kilometer Array Pathfinder (ASKAP) radio telescope to search for Fast Radio Bursts discovering 20 in a year, almost doubling the number previously detected. Their analysis suggests that their characteristics evolve over time.
First detected in 2007 by analyzing archive data collected in 2001, Fast Radio Bursts are still a mystery because such powerful radio emissions require an estimated energy that’s about what the Sun emits in 80 years despite their duration being a few milliseconds. For this reason, it was suggested that they’re emitted by neutron stars or black holes under certain conditions, but someone even suggests that these are artificial signals. Their origin is unknown so it’s right to assess the various possibilities, the problem so far has been to collect data but the situation is improving.
In October 2012 the ASKAP radio telescope was launched by CSIRO (Commonwealth Scientific and Industrial Research Organization), one of the precursors of the SKA, the next generation radio telescope, in which it will be integrated in a few years. ASKAP’s aim is to develop the technologies that will be used in the SKA and the experimental phase is delivering truly excellent results. The possibility of pointing its antennas on different parts of the sky allows to observe a surface of 240 degrees, in other words, about a thousand times the area of the full Moon, at once.
An instrument such as ASKAP is also great to detect Fast Radio Bursts, the reason why in a single year the number of known ones has almost doubled. Data analysis also enabled to study its characteristics to better understand what kind of journey they made crossing really huge distances, even billions of light years.
During its journey, the electromagnetic waves of a Fast Radio Burst can pass through gas clouds. In these cases, the different wavelengths that form are slowed in slightly different ways, with the consequence that they reach the Earth at slightly different times. The analysis of these times can provide information on the amount of matter the Burst passed through and this can also help to find amounts of matter not detected in other ways such as intergalactic clouds.
The excellent results already obtained by the ASKAP radio telescope offer the hope to gather enough data to understand the origin, which may not be only one, of Fast Radio Bursts. This task might be continued in a few years by its successor, the SKA radio telescope, which might detect an even greater amount of Fast Radio Bursts after the integration of the other precursor, the MeerKAT in South Africa.