Ghost Neutrinos: Born in the Coronas of Black Holes ⚡ экспресс
IceCube observations point to active galactic nuclei (AGN) as likely sources of astrophysical neutrinos. Near the central black hole, protons can be accelerated to high energies through magnetic reconnection and interact with the intense X-ray radiation from the corona, producing neutrinos. The possibility that the diffuse IceCube neutrino flux originates from jetless AGN with acceleration in the corona has been studied. A library of neutrino spectral templates was built on a grid of parameters: proton magnetization σ_p, coronal X-ray luminosity, and black hole mass. Due to strong coronal magnetic fields, synchrotron cooling of pions and muons is important. The model was combined with an AGN catalog consistent with observations in X-ray and mid-infrared bands at z=0–4 to calculate the diffuse flux. Coronal emission explains IceCube measurements up to energies of ~1 PeV, provided that ~10% of coronae have σ_p ~ 10^5, while the rest are distributed at lower values. At higher energies, the neutrino emission is suppressed, so an additional population is needed, and AGN with jets are strong candidates.
At the center of many galaxies lies a black hole — predicted by Schwarzschild. Around it churns a scorching corona, similar to the Sun's but a billion degrees hot. Here, neutrinos are born — ghost particles (first guessed by Pauli) that can pass through a light-year of lead.
Protons, accelerated by the corona's magnetic fields, slam into X-ray light and transform into neutrinos. Previously, it was thought that such particles were spewed by powerful plasma jets, but data from the Antarctic IceCube Observatory showed otherwise. Quiet galaxies without jets, with ordinary coronas, turned out to be the main source — they explain almost the entire neutrino flux up to the peta-electronvolt range.
Only for record-breaking energies is this cauldron not enough — then galaxies with relativistic jets step in. By combining observations of these 'ghosts' with theory, we paint a complete picture of their origin.
🎯 To stop a neutrino, you'd need a lead shield one light-year thick — but even that's no guarantee.
🎬 In science fiction, neutrinos are the ideal courier through planets; in reality, they bring news from the blazing coronas of black holes.