” When we saw the first results, we might not believe it, and at initially, we even believed that we had made an estimation error.”– Dr. Marcin Gawronski
A cluster of ancient stars (left) close to the spiral galaxy Messier 81 (M81) is the source of extraordinarily brilliant and brief radio signals. The Fast Radio Bursts (FRBs) are millisecond-long bursts of radiation taped on radio waves. Astronomers agree that quick radio flashes are the result of violent procedures occurring in the immediate vicinity of highly magnetized neutron stars, it is still unclear why most of them appear as single signals, while other sources can be observed on radio waves repeatedly. “Another issue is that radio telescopes “see” quite a large field of the sky, e.g., ours in Piwnice covers a location half the size of the Moons disk in the radio band, which we generally use for FRB observations. “In a sense, we act in parallel to EVN (European Very Long Baseline Interferometry Network), as we attempt to gather European radio telescopes outside the time allocated for standard observations within this consortium, to which, of course, the NCU Institute of Astronomy belongs together with the RT4 radio telescope.”
If we reject the possibility that there are star wars taking place quite near us, in which planets are damaged– and such a hypothesis may not be straight out of sci-fi movies, given that lots of researchers take into account that FRBs may be technosignatures– then there are a number of other hypotheses.
” Theoretically, a brand-new magnetar could have been born from an old star, or more exactly from the explosion of a white dwarf. This unstable dwarf takes off in an atomic surge, during which a neutron star may also be formed, such as a magnetar,” describes Dr. Gawronski. “However, it is not such an easy explanation: if there was a supernova surge in a globular cluster (however of a different type than the death of huge stars), it needs to have taken place not so long earlier on a cosmic scale.
The other possible explanation is the merger of two compact, old stars– white dwarfs and/or neutron stars– and the formation of a young object in the so-called kilonova phenomenon. The opportunity of such an event occurring in our “local” Universe is rather slim.
The astronomers discovery is as fascinating as it is mysterious. In the meantime, one thing is certain– the bursts are the outcome of some as yet unacknowledged phenomenon. The work of astrophysicists might contribute to its description and investigation. The results have actually been released in the distinguished journal Nature. The short article “A duplicating fast radio burst source in a globular cluster,” co-authored by Dr. Marcin Gawroñski, worrying the astronomers newest discovery is topic no. 1 in the current concern of the journal.
What were the FRB observations like?
Scientists use the EVN infrastructure, primarily the huge disk capabilities that were committed to the PRECISE consortium.
” We inspect which radio telescopes are offered at an offered time and apply for time– we arrange this ad hoc, about 3-4 weeks in advance,” states Dr. Marcin Gawronski. “We need to connect at least 5 radio telescopes together, developing a network. In these observations we used the largest European radio telescopes: a 100-meter meal in Effelsberg, Germany, and a 60-meter meal on Sardinia. They are big and therefore have a considerable gathering location, so we examined the data collected by them initially.”
After completing further series of observations, scientists must then study the recorded signal for the existence of FRBs as quickly as possible, and inform the EVN stations that picked data can be deleted as unimportant.
Recently, the system for observation, data collection and analysis has been enhanced. The English e-MERLIN radio telescope network has actually granted up to 400 hours of availability of its instruments to the PRECISE. Second of all, and no less significantly, thanks to financial investments in devices from the University Centre of Excellence “Astrophysics and Astrochemistry,” the researchers in Piwnice have the possibility to procedure and study the taped signal autonomously through their radio telescope.
” You can say that I am providing some servers a tough time, as they are working almost non-stop, processing substantial amounts of data,” says Dr. Gawronski. “Apart from the PRECISE job, there is likewise our internal research team keeping an eye on the known sources of FRB. We conduct observations by means of 3 radio telescopes: our RT-4 from Piwnice near Torun, the Dutch Westerbork and the Swedish Onsala. Thanks to these additional observations, we study the activity of the recognized FRB sources at frequencies above 1.4 GHz. The addition of a local computing node need to significantly broaden the capabilities of our research group.”
References:
” A duplicating quick radio burst source in a globular cluster” by F. Kirsten, B. Marcote, K. Nimmo, J. W. T. Hessels, M. Bhardwaj, S. P. Tendulkar, A. Keimpema, J. Yang, M. P. Snelders, P. Scholz, A. B. Pearlman, C. J. Law, W. M. Peters, M. Giroletti, Z. Paragi, C. Bassa, D. M. Hewitt, U. Bach, V. Bezrukovs, M. Burgay, S. T. Buttaccio, J. E. Conway, A. Corongiu, R. Feiler, O. Forssén, M. P. Gawronski, R. Karuppusamy, M. A. Kharinov, M. Lindqvist, G. Maccaferri, A. Melnikov, O. S. Ould-Boukattine, A. Possenti, G. Surcis, N. Wang, J. Yuan, K. Aggarwal, R. Anna-Thomas, G. C. Bower, R. Blaauw, S. Burke-Spolaor, T. Cassanelli, T. E. Clarke, E. Fonseca, B. M. Gaensler, A. Gopinath, V. M. Kaspi, N. Kassim, T. J. W. Lazio, C. Leung, D. Z. Li, H. H. Lin, K. W. Masui, R. Mckinven, D. Michilli, A. G. Mikhailov, C. Ng, A. Orbidans, U. L. Pen, E. Petroff, M. Rahman, S. M. Ransom, K. Shin, K. M. Smith, I. H. Stairs and W. Vlemmings, 23 February 2022, Nature.DOI: 10.1038/ s41586-021-04354-w.
” Burst timescales and luminosities as links in between young pulsars and fast radio bursts” by K. Nimmo, J. W. T. Hessels, F. Kirsten, A. Keimpema, J. M. Cordes, M. P. Snelders, D. M. Hewitt, R. Karuppusamy, A. M. Archibald, V. Bezrukovs, M. Bhardwaj, R. Blaauw, S. T. Buttaccio, T. Cassanelli, J. E. Conway, A. Corongiu, R. Feiler, E. Fonseca, O. Forssén, M. Gawronski, M. Giroletti, M. A. Kharinov, C. Leung, M. Lindqvist, G. Maccaferri, B. Marcote, K. W. Masui, R. Mckinven, A. Melnikov, D. Michilli, A. G. Mikhailov, C. Ng, A. Orbidans, O. S. Ould-Boukattine, Z. Paragi, A. B. Pearlman, E. Petroff, M. Rahman, P. Scholz, K. Shin, K. M. Smith, I. H. Stairs, G. Surcis, S. P. Tendulkar, W. Vlemmings, N. Wang, J. Yang and J. P. Yuan, 23 February 2022, Nature Astronomy.DOI: 10.1038/ s41550-021-01569-9.
Very quickly radio signals from a surprising source. A cluster of ancient stars (left) close to the spiral nebula Messier 81 (M81) is the source of short and extraordinarily brilliant radio signals. The image displays in blue-white a graph of how one flashs brightness altered throughout just tens of split seconds. Credit: Daniëlle Futselaar, artsource.nl
The Fast Radio Bursts (FRBs) are millisecond-long bursts of radiation taped on radio waves. They are exceptionally effective– for instance, throughout among the brightest flashes lasting five milliseconds, as much energy is radiated as our Sun generates in a month. The scale of the phenomenon is difficult to think of.
The very first radio bursts were “discovered” barely 15 years earlier. Up until April 2020, all the FRBs observed by astronomers came from cosmological distances of hundreds of millions of light years.
” FRBs are currently among the most popular topics in modern astrophysics. Discovered mistakenly in 2007 throughout an evaluation of archival information, and currently under intensive observation, they are still an excellent mystery,” describes Dr. Marcin Gawronski from the Institute of Astronomy at the Faculty of Physics, Astronomy and Informatics Nicolaus Copernicus University (Torun, Poland). “The results collected up until now make it possible to divide the FRB phenomena into different classes, however we still have actually not discovered whether they are emanations of one or lots of different physical procedures.”
Cosmic catch
Researchers are not 100 percent sure what causes the bursts. Astrophysicists have different hypotheses that might describe their formation, consisting of the presence of extraterrestrial civilizations. However, so far magnetars have been thought about to be the source of FRBs.
Source of mystical radio signals: an artists impression of a magnetar in a cluster of ancient stars (in red) near the spiral galaxy Messier 81 (M81). Credit: Daniëlle Futselaar, artsource.nl
” Magnetars are neutron stars with incredibly strong magnetic fields, they are formed after supernova surges,” states Dr. Gawronski. The only sources of this type understood to us are either the magnetic fields of a cluster of neutron stars– these magnetars– or the gravitational energy of black holes.”
Astronomers agree that fast radio flashes are the result of violent processes taking place in the instant vicinity of highly allured neutron stars, it is still unclear why many of them appear as single signals, while other sources can be observed on radio waves repeatedly. In some cases, the bursts are in addition identified by routine activity, i.e., they happen at routine time periods. This, however, just helps in preparing observations.
There are likewise many difficulties that astronomers have to deal with in FRB observations. “Studying FRB activity is extremely difficult since flashes are random phenomena. It appears a bit like fishing– we cast a fishing rod and wait. So, we established radio telescopes and we need to wait patiently,” says Dr. Gawronski. “Another issue is that radio telescopes “see” rather a big field of the sky, e.g., ours in Piwnice covers an area half the size of the Moons disk in the radio band, which we generally utilize for FRB observations. There are numerous things over such a large location, so it is hard to pinpoint one specific flash. Another issue is the massive quantity of data that we collect during such observations– we can tape up to 4 gigabits of data per 2nd, so we need huge storage capacities. We have to process, examine and erase this data on a continuous basis to make space for the next.”
Dr. Marcin Gawronski from the Institute of Astronomy at the Faculty of Physics, Astronomy and Informatics Nicolaus Copernicus University (Torun, Poland). Credit: Andrzej Romanski/NCU, Torun, Poland
As you can see, there are numerous puzzles and troubles gotten in touch with fast radio bursts Astrophysicists are dealing with models to describe this phenomenon, but the recent discovery, in which Dr. Marcin Gawroñski also took part, brings yet another mystery to be fixed.
Cosmic inquisition
Last year a worldwide group of astronomers, including Dr. Gawronski, pointed radio telescopes towards the galaxy M81.
” It is a big and close to us galaxy, comparable to the Milky Way– it lies about 12 million light-years far from us, in summer season when the weather condition is excellent you can see it with a regular set of binoculars, and e.g., with the Hubble telescope you can observe single stars in it,” describes Dr. Gawronski. “Canadians from the CHIME task told us that there gave quick radio bursts in the area of this galaxy, and whats more, a few of its residential or commercial properties indicated that this object was associated with the M81. We thought it would be a terrific chance to try to find out what specifically created the FRBs.”
The observations were made by scientists working mainly in the PRECISE consortium.
” This is a group of scientists whose main objective is to find FRB sources, estimate the distances to them, and study the homes of the environment in which FRBs are put. In this way, we can attempt to say something about the advancement of the sources of quick bursts and the really processes in which FRB items are created,” says Dr. Gawronski. “In a sense, we act in parallel to EVN (European Very Long Baseline Interferometry Network), as we try to gather European radio telescopes outside the time designated for basic observations within this consortium, to which, naturally, the NCU Institute of Astronomy belongs together with the RT4 radio telescope.”
Dr. Marcin Gawronski from the Institute of Astronomy at the Faculty of Physics, Astronomy and Informatics Nicolaus Copernicus University (Torun, Poland). “In these observations, we used the largest European radio telescopes: a 100-meter dish in Effelsberg, Germany, and a 60-meter meal on Sardinia and RT4 in Piwnice,” states Dr. Gawronski. Credit: Andrzej Romanski/NCU, Torun, Poland
The researchers are extremely lucky. The very first time they pointed their radio telescopes at the vicinity of the M81 galaxy, they discovered a series of 4 bursts. It wasnt long before they caught two more. However, the new findings came as a surprise to the scientists.
” When we saw the very first outcomes, we might not think it, and at initially, we even thought that we had actually made a calculation error. Due to the fact that none of us anticipated such a thing,” says Dr. Gawronski.
A child among the old?
The first frustration came at the beginning– a cluster of this type consists of a huge number of largely packed stars, so it was difficult to identify the particular things that was the source of the FRB, even with the help of the Hubble orbiting telescope. More surprisingly, globular clusters are composed of really old stars, formed up to 10 billion years ago– they are the oldest star systems in the galaxies.
” Many concerns pertained to our minds: where did the magnetar come from there? We presumed that it must have been the source of the bursts. In reality, the magnetar could not have existed. And if it was, it could not have actually been formed in a classical method, i.e., following a surge of an enormous star,” explains Dr. Gawronski. “Such enormous stars live for an extremely short time and within an estimated time of a number of tens of millions of years after their development they end their lives in a very remarkable phenomenon, called a supernova surge. It is known that stars do not form in globular clusters for a very long time, so no new magnetars can form there during a supernova phenomenon.”
