Neutrinos reveal hidden particle accelerators around black holes
Physicists have detected high-energy neutrinos from a nearby galaxy, suggesting its central black hole contains a powerful particle accelerator hidden inside a dense gas cloud. The discovery opens a new way to study extreme physics near black holes and could help predict where other cosmic particle accelerators hide—knowledge that matters for next-generation telescope design and fundamental physics research.
Originaltitel: Neutrino and gamma-ray emissions from NGC 1068
<p>IceCube has recently reported the detection of ∼1–10 TeV neutrinos from the nearby active galaxy, NGC 1068. The lack of TeV-scale emission from this source suggests that these neutrinos are generated in the dense corona that surrounds NGC 1068’s supermassive black hole. In this paper, we present a physical model for this source, including the processes of pair production, pion production, synchrotron, and inverse Compton scattering. We have also performed a new analysis of <em>Fermi</em>-LAT data from the direction of NGC 1068, finding that the gamma-ray emission from this source is very soft but bright at energies below ∼1 GeV. Our model can predict a gamma-ray spectrum that is consistent with Fermi-LAT observations when the magnetic field within the corona of this active galactic nucleus (AGN) is quite high, namely 𝐵 ≳6 kG. To explain the observed neutrino emission, this source must accelerate protons with a total power that is comparable to its intrinsic x-ray luminosity. In this context, we consider two additional nearby active galaxies, NGC 4151 and NGC 3079, which have been identified as promising targets for IceCube.</p>