A Tour of Sagittarius A*

Narrator (April Hobart, CXC): One of the biggest mysteries in astrophysics today is figuring out where mysterious particles called neutrinos come from. Neutrinos are tiny particles that carry no charge and interact very weakly with electrons and protons. Unlike light or charged particles, neutrinos can emerge from deep within their sources and travel across the universe without being absorbed by intervening matter or, in the case of charged particles, deflected by magnetic fields.

The Earth is constantly bombarded with neutrinos from the sun. However, neutrinos from beyond the solar system can be millions or billions of times more energetic. Scientists have long been searching for the origin of these very energetic neutrinos.

Now scientists have a new clue in their hunt for the source of neutrinos. By analyzing data from three X-ray telescopes, including Chandra, researchers have found a connection between flares generated by the supermassive black hole at the center of the Milky Way and the arrival of high-energy neutrinos at a detector under the South Pole. In fact, the facility in Antarctica, called the IceCube Neutrino Observatory, saw one of these high-energy neutrinos less than three hours after Chandra detected the largest flare ever from the Milky Way's supermassive black hole. The Swift and NuSTAR X-ray telescopes also recorded flares that were later tied to IceCube neutrino detections.

While it's too early to say if the Milky Way's black hole is definitively generating high-energy neutrinos, the latest results are a promising lead for scientists to follow.