Astronomers refined the location of the source of repetitive fast radio bursts

On Geektimes regularly published materials about the so-called fast radio bursts (Fast Radio Burst, FRB). So scientists call single radio pulses, the duration of which is only a few milliseconds. Moreover, the nature of these pulses is unknown. Discovered them not so long ago - in 2007. And so far they are a mystery that scientists can not solve.

Now experts were able to localize the source of radio bursts using the Very Large Array Antenna Grid (Very Large Array, VLA). This is a composite radio telescope of 27 radio telescopes, which operate as a single multi-vibrator complex antenna. In fairness, it should be noted that in 2012, scientists have already determined the approximate location of the source of these strange radio signals, but now its location has been localized much more precisely, improving the accuracy of a thousand times.

Unfortunately, the nature of the signals could not be clarified even now. The main problem is that these radio signals are not repeated, so finding out exactly which region of the Universe they came from was not possible. Accordingly, it is difficult to clarify the nature of these radio signals, because if it is not clear where they come from, it is impossible to find out what is their source. There are many assumptions, one of which is quite plausible. We are talking about colliding neutron stars, which subsequently destroy each other, giving just such a signal.
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Earlier, it was suggested that the source of the signals could be something on Earth, and in general, all this hype is something like the registration of microwave radiation, which was previously reported. In April 2015, an article about the nature of peritons, a type of fast radio pulses, found only on the Parks radio telescope, appeared in the archive of electronic preprints arxiv.org. It turned out that almost all such impulses are artifacts. They were observed under certain provisions of the Parks radio telescope at the time of violation of the rules of operation of one of the two microwave ovens in the kitchen for employees and in the room for visitors, namely, early, before completion of work, the door was opened. But this explanation is not suitable for all fast radio flashes, since the signals were registered simultaneously by the Green-Bank radio telescope at 2 GHz and the Arecibo radio telescope at 1.4 GHz.

In March 2016, scientists first discovered repetitive radio bursts. According to experts, these were the first FRBs outside of our galaxy and the first FRBs that constantly came from the same source. Previously, source signals were recorded in 2015. Registration of radio signals was performed thanks to the Arecibo telescope. Archival data helped to find out that the oldest signals from this place were recorded in 2012.



Over the past six months, scientists have spent about 83 hours of time in the Very Large Antenna Grid to monitor the source of the radio signals. During this time, he gave 9 signals, which, as mentioned above, were also recorded by the Arecibo radio telescope. Unfortunately, no periodicity has been identified. Otherwise, scientists might understand what is the source.

New observations have confirmed that the FRB, registered now, are coming from outside our galaxy. Approximate calculations show that the source is located at least 5.5 billion light-years from us, and possibly further.

So what is the source?

The authors of the current study argue that the source may well be the core of a galaxy. Perhaps, experts say, radio signals appear as a result of the activity of a supermassive black hole located in the center of this galaxy. She herself is small in size, and its mass should not exceed a billion masses of the Sun. This is comparable to the size and mass of the Small Magellanic Cloud, one of the small satellites of our Milky Way. We cannot see the source of repetitive FRBs.

Scientists suggest that during the emission of energy that feeds FRB, radiation of other bands (including visible light) may also go into space. In this case, using a conventional high-power telescope, you can detect the source of the flash. However, when detecting FRB lenses of telescopes, it is necessary to immediately point to the source in order to fix possible radiation of other types.

Another source of radio signals identified in 1500 light years from the source, referred to above. So far it is unclear whether these are interrelated elements, or whether it is the same object in general. Most likely the last, since we are talking about very long distances and the equipment simply cannot show sufficient accuracy. Or maybe the measurement data are correct, and we are seeing the interaction of closely spaced neutron stars and the center of a dwarf galaxy.

There is a possibility that an object or objects generate radio signals much more often than those that we record. It is just that the strength of other signals is less, and the equipment is unable to register them. "We are considering all the options, without giving priority to any of the possible explanations," - said the representatives of the project.

Perhaps in the near future, astronomers will still be able to figure out what source of regular FRB we are seeing now. This will contribute to more accurate equipment, the development of which is underway now, plus the involvement of new specialists to solve this problem.

There is, of course, another possibility — that these signals are generated by some civilization that is far from us. But in this case, we can still assume that the source of the FRB are any natural objects - the same neutron stars.

DOI: doi: 10.1038 / nature20797