Astrophysicists managed to tie neutrinos of ultrahigh energies with flashes of quasars

astrophysicists have carried out a joint analysis of the luminosity
of active galactic nuclei in the radio and time of registration of neutrinos high
energies. It turned out that these two phenomena are interrelated: neutrinos reach the Earth
during periods of increased radioacti quasars. The authors were able to define four
particular source, which with high probability produce such neutrinos.
All selected quasars have bright jets, which are oriented in the direction
Of the earth, write the authors in the journal The Astrophysical Journal.

Neutrinos are the lightest of the class having a mass of particles in
The standard model of physics of the microworld. These objects have extremely small cross-section
interaction with other particles, causing their registration exclusively
difficult even with the high flows. At the moment, only a few space
objects definitely identified as the sources of neutrinos, including the Sun,
supernova 1987A and the blazar TXS 0506+056, which was the first particular source of neutrinos of high energy.

Astrophysicists have long proposed the idea of the birth of the neutrino
high energies in active galactic nuclei, which, in particular, include
blazey. Primarily this is due to suitable conditions in such
facilities: there are powerful magnetic fields and shock waves that contribute to
the acceleration of charged particles and subsequent interactions between them can
lead to neutrinos.

To prove this hypothesis is not easy, as virtually the first
a suitable detector of the neutrino is the IceCube Antarctic telescope, whose construction was
completed in 2010. However, this huge installation log events
quite rare, and the accuracy of recovery of the source parameters (coordinates
source and particle energies) are often insufficient to draw firm conclusions.

astrophysics from Astro space center LPI, MIPT and
Institute for nuclear research of RAS, with the participation of Yuri Kovalev (Yuri A. Kovalev) tested this idea statistical
the method, after a joint analysis of data on registrations of neutrinos with energies
above 200 teraelectronvolt and brightness of active galactic nuclei in the radio.
The authors came to the conclusion that between events there is a correlation, and sources
be the nucleus of active galaxies with temporarily higher brightness in the center. Due to the low
sampling to accurately determine all sources failed, but scientists have named
the four most likely candidates is the quasars 3C 279, NRAO 530, PKS 1741-038 and OR 103.

As a source of data about neutrinos, the researchers took
information about the registration of particles with energies above 200 TeV, the direction to the sources
which is known with accuracy not worse than 10 square degrees, — such events in the
database IceCube
turned out to be 56 (the share of non-astronomical background processes events
is estimated at least a third). This energy threshold was chosen, since the available
the data show the existence of two neutrino component
different characteristic energies, and above 200 TeV one of them starts
to dominate.

Another source of information were the observations of active galactic nuclei
in the radio. Astrophysics looked at the coincidence of coordinates of sources
neutrinos with such objects, and used historical data about the luminosity of a number of
such celestial bodies. the First dataset, covering the whole sky, was obtained
the various systems of the interferometers, and the second — then radio telescope
The RATAN-600, which is most sensitive in the range of declination -30 to +43
degrees.

The analysis showed that neutrinos come statistically significant
with areas where there are active galactic nuclei whose Central brightness
in the radio band is higher than that of objects of this type in the middle.
The random probability of such a coincidence was equal to 0.2 percent. Also
it turned out that during registration of the neutrino radiation from these galactic nuclei
it was more powerful than in other observational epochs for the same object, that is, they
generated high-energy particles in the phase of the burst.

The results bring scientists to unravel the nature of cosmic sources
neutrinos, and also suggests why this could not be done
the company informed. So, one of the most active areas of research was the search for correlations
between the sources of neutrinos and gamma rays. However, the luminosity in the gamma range
for the selected objects differs by orders of magnitude, which indicates the opacity
substances in the middle of these bodies to gamma radiation and the inefficiency of the search for similar correlations.

Additional information about the nature of high-energy neutrinos
astrophysicists expect to receive after the full commissioning of the new
neutrino telescopes, such as Baikal-GVD, KM3NeT and which can accurately
to recover the coordinates for a larger number of events. However, with this in
last time around the world fold program of ongoing monitoring
active galactic nuclei separate radio telescopes. This can complicate the task
since in the absence of such observations is unclear, it’s whether neutrinos during
bursts of activity of the nucleus or not.

We wrote extensively about the first registration of neutrinos of ultrahigh energy to the material “Ice”neutrino. Later scholars have put forward the idea that this event is associated with collisions of flows in the jet of the blazar. To do this, researchers for the first time managed to determine the source of extragalactic neutrinos — they also turned out to be a blazar.

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