• The Squid Galaxy (NGC 1068) emits a high amount of neutrinos compared to gamma rays, which is unusual.
• Researchers propose that helium fragmentation in the galaxy's jet is the source of these excess neutrinos.
• The discovery provides insights into the extreme environments surrounding supermassive black holes and could lead to further understanding of radiation and elementary particles.

A recent study has proposed a novel explanation for the high neutrino emission and weak gamma-ray emission observed in the Squid Galaxy (NGC 1068). Unlike other active galaxies where neutrino production is linked to gamma-ray emission, the Squid Galaxy presents an anomaly. Researchers suggest that collisions between helium nuclei and ultraviolet photons result in fragmentation and neutron decay, producing neutrinos without significant gamma-ray production. This insight sheds light on the extreme conditions around supermassive black holes.

• What: A new theory explains the unusual neutrino-to-gamma-ray ratio in the Squid Galaxy (NGC 1068) through helium fragmentation and neutron decay.
• Who: Koichiro Yasuda (UCLA), Alexander Kusenko (UCLA and Kavli IPMU), Yoshiyuki Inoue (University of Osaka), IceCube Neutrino Observatory.
• When: Research published recently in Physical Review Letters, observations ongoing.
• Where: Squid Galaxy (NGC 1068), 47 million light-years away; IceCube Neutrino Observatory, Antarctica.

The discovery of a novel mechanism for neutrino production in the Squid Galaxy (NGC 1068) provides new insights into the extreme environments around supermassive black holes. The traditional explanation, based on proton-photon collisions, fails to account for the high neutrino emission and low gamma-ray emission observed in the galaxy. The helium fragmentation theory offers a more complete picture, potentially leading to the identification of previously unnoticed astrophysical neutrino sources. This underscores the importance of multi-messenger astronomy, which combines neutrino, gravitational wave, and light observations to understand the universe.

We have telescopes that use light to look at stars, but many of these astrophysical systems also emit neutrinos. To see neutrinos, we need a different type of telescope, and that’s the telescope we have at the South Pole.

Hydrogen and helium are the two most common elements in space. But hydrogen only has a proton and if that proton runs into photons, it will produce both neutrinos and strong gamma rays. But neutrons have an additional way of forming neutrinos that doesn’t produce gamma rays. So helium is the most likely origin of the neutrinos we observe from NGC 1068.

We don't know very much about the central, extreme region near the galactic center of NGC1068. If our scenario is confirmed, it tells us something about the environment near the supermassive black hole at the center of that galaxy.

The helium fragmentation theory provides a compelling explanation for the excess neutrino emission in the Squid Galaxy (NGC 1068), offering a new understanding of the processes occurring near supermassive black holes. Future neutrino detections will help validate this theory and potentially uncover more hidden astrophysical neutrino sources. This discovery highlights the growing importance of neutrino astronomy and its role in furthering our knowledge of the universe.