Astronomers have uncovered the origins of the most mysterious signals from space: what could they be?

To this day, scientists do not fully understand how fast radio bursts (FRBs) originate, but new research sheds light on the source of these mysterious radio signals that come from all corners of the cosmos. The findings of the study are published in the journal Nature, as reported by ScienceAlert.

Until now, scientists knew very little about fast radio bursts (FRBs), which are short flashes of electromagnetic radiation detectable in radio waves. Essentially, these are radio impulses that have an average frequency of 1400 Hz. However, FRBs appear and disappear within fractions of a second, making them some of the most enigmatic signals sent to us by the Universe. It is known that the sources of FRBs are located millions and billions of light-years away from Earth.

One of the main theories suggests that FRBs are produced by magnetars, a type of neutron star with the strongest magnetic field in the Universe. It is believed that the interaction between a star's magnetic field and its gravity leads to the occurrence of "starquakes," which in turn generate FRBs. However, not all of these radio flashes behave in the same manner, indicating that there are other mechanisms for their creation.

According to the authors of the study, examining the galaxies from which these radio signals originate helped to identify the environmental conditions that favor their emergence. A thorough analysis of the galaxies from which FRBs have arrived revealed that fast radio bursts typically occur in galaxies with a high number of young stars. However, these galaxies also tend to have a very large mass, which is quite rare.

On the other hand, young stars are often very massive and have a short lifespan before exploding as supernovae. This results in the formation of neutron stars, including magnetars. Astronomers concluded that a galactic environment filled with young stars is significant for the creation of FRB sources.

Researchers also discovered that the amount of metals in a galaxy plays a role in this process. Massive galaxies typically have more metals than their less massive counterparts and generally produce more massive stars. In astronomy, metals (which chemists might not appreciate) refer to chemical elements that are heavier than hydrogen and helium, the fundamental building blocks of all matter in the Universe.

At the same time, scientists note that supernovae occur in galaxies at nearly the same rate as new stars are born. Therefore, if magnetars create FRBs, the distribution of fast radio bursts should correspond to the distribution of supernovae in the galaxy, but this is not the case. Thus, scientists believe that this type of neutron star is not the primary source of these strange radio impulses.

Conversely, magnetars that generate FRBs may have been formed as a result of the merger of binary stars. This can happen in galaxies where there are many massive stars. This research does not provide a definitive answer regarding the sources of FRBs but supports arguments in favor of magnetars and suggests that a unique galactic environment contributes to the origin of these signals.