A group of astrophysicists discovered that a high-energy neutrino came from a place where a black hole “swallowed” a star. To produce these elusive particles, accelerated cosmic rays are needed, so the source may be the same.
In 2018, the IceCube Observatory in Antarctica, in collaboration with telescopes around the world, announced a landmark discovery: the first evidence of high-energy neutrino and cosmic ray sources: blazar TXS 0506 + 056, a huge galaxy with A black hole and a jet of particles directed directly at the earth.
Now one Second source this type: AT2019dsgIn this case, a black hole “engulfs” a star that is too close.Astrophysicists call this phenomenon Tidal destruction event (TDE, Expressed in English acronyms), the star in it is “spaghetti” and is attracted to a large extent by the gravitational force of the hole.
Researchers from more than 30 institutions Robert Stein From Deutsches Elektronen SYnchrotron (Dis) In Germany, I found a High energy neutrino The same direction as AT2019dsg, which is related to the most active particles in the universe: Ultra-high energy cosmic rays.The discovery was published in this week’s magazine Natural astronomy.
“We have Modeling data The electromagnetic component AT2019dsg of the TDE was found to have Suitable environment for accelerating particles and generating neutrinos“Stein emphasized to SINC and explained:” Cosmic rays are charged particles produced by cosmic particle accelerators. When these accelerated cosmic rays interact with photons or light, neutrinos are produced. Neutrinos cannot be produced without cosmic rays. Therefore, if TDE produces high-energy neutrinos, they must also produce cosmic rays. “
The researchers pointed out that, as discovered in 2018, the Big Bang cannot produce more than 30% of the high-energy neutrinos detected by IceCube, so most of them must come from elsewhere:Where is the problem. At present, AT2019dsg is the second source of high-energy neutrinos and provides the first evidence that TDE also produces some neutrinos”.
The signal of this new signal source was discovered with an optical telescope ZTF (U.S.) Palomar Observatory (Zwicky Transient Facility) is within the framework of the neutrino monitoring program, but then 13 other instruments have studied it at different wavelengths, including Ice cubes From Antarctica Liverpool TV From Tenerife, from space to observatory XMM-Newton ESA and Swift Fermi-Rattle From NASA.
The co-author told SINC: “Now, we will continue to make more observations and try to find more sources of high-energy neutrinos to determine whether TDE generally produces neutrinos, or whether AT2019dsg is an unusual event.” Cesar Rojas Bravo From the University of Santa Cruz, California.
Another possible source of cosmic rays
Recent partner HAWC The Gamma-ray Observatory (High Altitude Water Cherenkov) in Mexico has also discovered another candidate galaxy source that produces ultra-high-energy cosmic rays.
The research was published in Astrophysical Journal Letter, Showing the detection of very high energy photons from the source HAWC J1825-134, Its energy spectrum reaches at least 200 meg-electron volts (TeV) energy.
According to the author, it includes Francisco Saleta Grus From the Institute of Particle Physics (International Finance Corporation, CSIC-University of Valencia) believes that the emission should be produced by higher energy cosmic rays, the energy of which is approximately petaelectronvolt (Hepatitis B virus) To show the possible sources of these content.
Mexico HAWC Gamma Ray Observatory. / HAWC
Researchers say that the gamma rays observed by HAWC are the result of the interaction of these high-energy cosmic rays with molecules in a dense matter region (molecular cloud).
“HAWC J1825-134 observations make this source a clear candidate for the emission of high-energy neutrinos.” stand out Like other authors, Salesa believes that some telescopes currently in use at the bottom of the Mediterranean Sea, such as the IceCube or KM3NeT telescope, can confirm this discovery.