West LA Times

The galaxy M87, located in the Virgo constellation, gained fame in 2019 when the Event Horizon Telescope captured the first-ever image of a black hole at its center. Recently, an international research team, including members from UCLA, observed a significant gamma-ray flare from this supermassive black hole. This event is notable for being seven orders of magnitude larger than the black hole's event horizon.

Weidong Jin, a postdoctoral researcher at UCLA and corresponding author of a paper published in Astronomy & Astrophysics, stated: “We still don’t fully understand how particles are accelerated near the black hole or within the jet.” He added that their study presents comprehensive spectral data to shed light on these processes.

Gamma rays are packets of electromagnetic energy produced by energetic environments like those around black holes. The recent flare from M87 emitted photons with energy levels reaching several teraelectronvolts—billions of times more energetic than visible light photons. Such flares offer insights into particle acceleration near black holes.

The analysis was supported by VERITAS—a ground-based gamma-ray instrument—and involved contributions from over two dozen observational facilities such as NASA’s Fermi-LAT and Hubble Space Telescope. These observatories participated in a campaign to observe M87 across multiple wavelengths.

Jin explained that one key dataset used was called spectral energy distribution: “The spectrum describes how energy from astronomical sources, like M87, is distributed across different wavelengths of light.” This analysis helps uncover processes driving high-energy particle acceleration in the jet of the supermassive black hole.

Further investigation revealed variations in the position and angle of both the ring (event horizon) and jet position. Jin noted: “One of the most striking features of M87’s black hole is a bipolar jet extending thousands of light years from the core.” The study aimed to identify where particles causing such flares are accelerated and could help resolve debates about cosmic ray origins detected on Earth.