Read more at: https://phys.org/news/2018-07-century-old-riddle-resolveda-blazar-source.htmlAn international team of scientists has found the first evidence of a source of high-energy cosmic neutrinos, ghostly subatomic particles that can travel unhindered for billions of light years from the most extreme environments in the universe to Earth.
The observations, made by the IceCube Neutrino Observatory at the Amundsen-Scott South Pole Station and confirmed by telescopes around the globe and in Earth's orbit, help resolve a more than a century-old riddle about what sends subatomic particles such as neutrinos and cosmic rays speeding through the universe.
Since they were first detected over one hundred years ago, cosmic rays—highly energetic particles that continuously rain down on Earth from space—have posed an enduring mystery: What creates and launches these particles across such vast distances? Where do they come from?
Fermi was the first telescope to identify enhanced gamma-ray activity from TXS 0506+056 within 0.06 degrees of the IceCube neutrino direction. In a decade of Fermi observations of this source, this was the strongest flare in gamma rays, the highest-energy photons. A later follow-up by MAGIC detected gamma rays of even higher energies.
Particles of particular interest to the IceCube team pack a more energetic punch. The neutrino that alerted telescopes around the world had an energy of approximately 300 TeV. (The energy of the protons circulating in the 26.7-kilometer ring of the Large Hadron Collider is 6.5 TeV.)
Involute said:Vanadium:
Since the charged particles that comprise cosmic rays would travel a different path through space than neutrinos from the same source, would we ever expect to see both types of particles arrive at Earth at the same time from the same direction, or even different directions?
Thanks, but the first doesn't answer my question and the second is over my head, though the abstract suggests it doesn't answer it either.diogenesNY said:Coverage in the NY Times: https://www.nytimes.com/2018/07/12/science/space-neutrinos-blazar.html
and the article in Science: http://science.sciencemag.org/content/early/2018/07/11/science.aat2890
diogenesNY
So, to slightly rephrase my original question, why "would we ever expect to see both types of particles arrive at Earth at the same time from the same direction, or even different directions?"nikkkom said:Sure, charged particles' direction of travel is sufficiently messed up by interstellar / intergalactic magnetic fields to make it impossible to track their origin.
This observation was of uncharged particles (gamma rays and neutrinos), whose direction of travel can only be altered by a rather strong gravitational field.
A blazar is an extremely luminous and distant galaxy that emits powerful jets of high-energy particles. These jets are produced by a supermassive black hole at the center of the galaxy.
Blazars are believed to be one of the primary sources of cosmic neutrinos, which are subatomic particles that can travel vast distances without being affected by magnetic fields or other obstacles. The high-energy particles in blazar jets can interact with matter and produce cosmic neutrinos.
Scientists have observed a correlation between the locations of blazars and the locations of cosmic neutrinos detected on Earth. This suggests that blazars are indeed producing the cosmic neutrinos that we have observed.
Scientists use large detectors, such as the IceCube Neutrino Observatory located in Antarctica, to detect cosmic neutrinos. When a cosmic neutrino passes through the Earth and interacts with the detector, it produces a faint flash of light that can be recorded and analyzed.
This confirmation provides valuable insights into the origins of cosmic neutrinos and the processes happening in extreme environments, such as blazars. It also opens up new avenues for studying the high-energy universe and understanding the fundamental physics behind these elusive particles.