Gamma-ray bursts are the mostthe brightest and most powerful explosions in the universe. Scientists do not know much about their nature, but a group of researchers from the University of Charleston (USA), who studied the data of several similar events, claims that they contain anomalies that can be interpreted as the reverse flow of time. According to scientists, their observations do not allow to assert this with complete probability, however, no theoretical model describes the observed phenomena, the Astrophysical Journal article says.
For the first time, gamma radiation was discovered in 1968US satellites destined for the registration of Soviet nuclear tests. Scientists can not say exactly what is their cause, but the duration of gamma-ray bursts observed today can be from a few milliseconds to several hours.
Thanks to the discovery of gravitational waves createdcolliding neutron stars, we were able to find out at least one of their probable sources. Nevertheless, astrophysicists argue that these sources should be much more. According to the assumptions, gamma-ray bursts can be echoes of at least several cosmic cataclysms: the transformation of very massive stars into compact neutron stars, or quark stars (hypothetical objects never discovered), or into black holes, incidentally generating supernovae and hypernovas.
The difficulty in studying gamma-ray bursts isthat we can determine them only when their rays move directly in our direction. At the same time, gamma-ray emissions are most often (fortunately) occurring several billion light-years from us, therefore we are not able to predict their appearance. Moreover, observation of them requires the use of very sensitive equipment, often of an optical sense, so the problem of the presence of noise contained in the signal of these flashes is not excluded. And yet this does not mean that the flash itself is difficult to detect. Just the opposite. Such an event is very difficult not to notice. For example, only the SWIFT orbital observatory of the NASA aerospace agency for the period from 2004 to 2015 found about 1000 bursts of gamma radiation in different parts of space.
A team of astrophysicists from the University of Charlestonunder the leadership of John Hackkil decided to analyze the data of the six brightest gamma-ray bursts observed from 1991 to 2000 using the BATSE tool at the Compton Observatory (USA), which studies gamma radiation. As part of the study, scientists discovered a new and completely unexpected detail of gamma-ray bursts. Depending on which telescope (with low and high sensitivity) was used to observe these events, the spectrum of these cosmic phenomena looked different. The researchers noted that the excessively high brightness of gamma-ray flashes can smear their spectrum, hiding certain details in its structure, capable of suggesting what causes these phenomena.
Data analysis of all six outbreaks showed that theyhave a complex structure, not like a typical flat spectrum of gamma-ray bursts. At the same time, their signals contained anomalies that, as it turned out, cannot be explained from the standpoint of a single theoretical model. These signals were special wave-like structures that were rotated in time, as if their beginning was at the end of an outbreak, and the end - in the first moments of the star's explosion.
“We do not claim that this phenomenon is reallyexists in reality and violates the laws of causality. It is possible that this radiation generated particle beams or a shock wave, which was faced with the emission of gamma radiation and reflected back. Neither theoretical model describes either scenario, ”says John Hakkila.
To check for errors and coincidences, scientists are stillonce the data were cleared of noise, but a static analysis confirmed the correctness of the calculations, indicating the presence of processes that are not yet known to us in the production of gamma-ray bursts.
Scientists put forward several assumptionsseen In addition to hitting the jet, something similar, as noted by Hackyll, can occur if the flash light passes through a gravitational lens generated by a newborn black hole. In addition, similar signals may be noted if gamma-ray emissions pass through several giant ring-shaped structures from the gas surrounding the dead star.
Find out which of the options is correct will help new observations of other gamma-ray bursts, as well as the study of such anomalies, scientists note.