Astrophysicists capture astonishing images of gamma-ray flare from supermassive black hole M87

The jet emanating from the center of M87 is seven orders of magnitude, or tens of millions of times, larger than the event horizon or the surface of the black hole itself. Bright bursts of high-energy emission with energies far higher than those typically detected by radio telescopes from the black hole’s region. The flare lasted about three days and probably emerged from an area smaller than three light days, or just under 15 billion miles.

Gamma rays are a group of electromagnetic energy, also called photons. Gamma rays have the highest energy of all wavelengths in the electromagnetic spectrum and are produced by the hottest and most energetic environments in the universe, such as the regions around black holes. Photons in the M87 gamma-ray flare had energy levels as high as several teraelectronvolts. Teraelectronvolts are used to measure the energy of subatomic particles, equivalent to the energy of a mosquito’s motion. That’s a huge amount of energy for a particle trillions of times smaller than a mosquito. Photons with energies of several teraelectronvolts are much more energetic than the photons that make up visible light.

As matter falls toward a black hole, it forms an accretion disk in which particles accelerate due to the loss of gravitational potential energy. Some are even redirected away from the black hole’s poles into powerful outflows called “jets,” driven by strong magnetic fields. This process is irregular and often results in rapid bursts of energy called “flares.” However, gamma rays cannot penetrate the Earth’s atmosphere. About 70 years ago, physicists discovered that gamma rays could be detected from the ground by observing the secondary radiation produced when they hit the atmosphere.

“We still don’t fully understand how particles are accelerated near black holes or within jets,” said UCLA postdoctoral researcher Weidong Jin, who is accompanying a paper describing the findings published by an international team of authors in Astronomy. Author & Astrophysics. “These particles are so energetic that they travel at nearly the speed of light, and we want to understand where and how they acquire this energy. Our study provides the most comprehensive spectroscopic data ever collected for this galaxy, and reveals the truth model on these processes.

Jin was involved in the analysis of the highest-energy portion of the data set, called very high-energy gamma rays, collected by VERITAS, a ground-based gamma-ray instrument operating at the Fred Lawrence Whipple Observatory in southern Arizona. UCLA played an important role in the construction of VERITAS (short for High Energy Radiation Imaging Telescope Array System), participating in the development of electronics to read the telescope’s sensors and the development of computer software to analyze telescope data and data . performance. This analysis helps detect flares, as shown by large photometric changes that deviate significantly from baseline variability.

More than two dozen high-profile ground- and space-based observing facilities, including NASA’s Fermi-LAT, Hubble Space Telescope, NuSTAR, Chandra and Swift telescopes, as well as three of the world’s largest imaging atmospheric insulators Lenkov Telescope Array (VERITAS, HESS and MAGIC) joined the second EHT and multi-wavelength event in 2018.

One of the key data sets used in this study is called the spectral energy distribution.

“The spectrum describes how energy from an astronomical source, such as M87, is distributed among different wavelengths of light,” Jin said. “It’s like breaking light into a rainbow and measuring how much energy is present in each color. This analysis helps us reveal the different processes that drive the acceleration of high-energy particles in supermassive black hole jets.”

Further analysis by the paper’s authors found significant changes in the position and angle of the ring (also known as the event horizon) and the position of the jet. This shows that the physical relationship between particles and event horizons affects the position of the jet at different size scales.

“One of the most striking features of the M87 black hole is the bipolar jet that extends thousands of light-years from the core,” King said. “This study provides a unique opportunity to investigate the emission of extremely high-energy gamma rays during the flare. Our findings could help resolve a long-standing debate about the origin of cosmic rays detected on Earth.