A team of scientists has detected the presence of a high-energy neutrino – a particularly elusive particle – in the wake of the destruction of a star while passing through a black hole. This discovery, reported in the journal Natural Astronomy, sheds new light on the origin of Cosmic rays from Ultrahigh Energy – the highest energy particles in the universe.
The work, which includes researchers from more than two dozen institutions, including New York University and Germany’s LOOSE research center, focused on neutrinos – subatomic particles produced only on powerful accelerators on earth.
Neutrinos – as well as the creation process – are difficult to detect, and it is remarkable to discover them, as well as those of Ultrahigh Energy Cosmic Rays (UHECRs).
Heart of Darkness: A view of the growth disk around the supermassive black hole, with ray-like structures flowing from the disk. The extreme mass of the black hole bends space-time, so that the back of the growth disk can be seen as an image above and below the black hole. Credit: DESY, Science Communication Laboratory
“The origin of high-energy cosmic neutrinos is unknown, mainly because they are difficult to determine,” explains Sjoert van Velzen, one of the lead authors of the article and a postdoctoral fellow in the Department of Physics at NYU during the discovery. “This result is only the second time that high-energy neutrinos have been returned to their source.”
Previous research by van Velzen, now at Leiden University of the Netherlands, and NYU physicist Glennys Farrar, co-author of the new Natural Astronomy paper, found some of the earliest evidence that black holes destroy stars in what are now known as Number of Disruption Events (TDEs). These findings form the basis for determining whether TDEs may be responsible for the production of UHECRs.
The research reported in Natural Astronomy support for this conclusion offered.
Smoke gun: After the supermassive black hole tore the star apart, about half of the star remnants were returned to space, while the rest formed a glowing growth disk around the black hole. The system shone brightly over many wavelengths and is thought to produce energetic, radiant effluents perpendicular to the growth disk. A central, powerful engine near the growth disk spit out these fast subatomic particles. Credit: DESY, Science Communication Laboratory
Previously, the IceCube Neutrino Observatory, a locator located by the National Science Foundation in the South Pole, reported the detection of a neutrino, the path of which was later detected by the Zwicky passing facility at Caltech’s Palomar Observatory.
Specifically, its measurements showed a spatial coincidence of a high-energy neutrino and light emitted to a TDE – a star consumed by a black hole.
“This suggests that these star-scattering events are powerful enough to accelerate high-energy particles,” Van Velzen explains.
As the star approaches the black hole, the enormous tidal forces stretch it further and further until it is finally shredded. Half of the star remains are returned to space, while the remaining part forms a rotating growth disk from which two strong outflows of matter shoot up and down. The system acts as a powerful accelerator of natural particles. Credit: DESY, Science Communication Laboratory
“The discovery of neutrinos associated with TDEs is a breakthrough in understanding the origin of the high-energy astrophysic neutrinos identified by the IceCube detector at the South Pole, the sources of which have so far been elusive,” adds Farrar at, which in a 2009 article suggests that UHECRs could be accelerated in TDEs. “The neutrino TDE coincidence also sheds light on a decade-old problem: the origins of Ultrahigh Energy Cosmic Rays.”
Reference: February 22, 2021, Natural Astronomy.
DOI: 10.1038 / s41550-020-01295-8
The research was supported by grants from the National Science Foundation (CAREER grant 1454816, AAG grant 1616566, PIRE Grant 1545949, NSF grant AST-1518052)