Astronomical Physical Jet “Trapped” in “Speed Trap”
In 1997, science fiction author Arthur C. Clarke selected the Seven Wonders of the World in a program on BBC, and one of these wonders was SS 433, a celestial body known for its unique X-ray emissions.
The astronomical body SS 433 is a binary star system containing a black hole and a star orbiting each other, and the strong gravity of the black hole pulls material from the surface of the star, forming what resembles “jet planes” of charged particles moving at speeds estimated at “one quarter of the speed of light.”
Although smaller than jets coming from larger galaxies, studying the jets of the astronomical body SS 433 is easier because it is closer to Earth. In 2018, the HAWC Observatory in Mexico discovered gamma-ray emissions from the jets of the astronomical body SS 433 for the first time, revealing particles accelerated to extreme energies. During a follow-up study conducted by the High Energy Stereoscopic System Observatory in Namibia, details of which were published in the journal “Science,” researchers found that the astronomical physical jet was “trapped” in a “speed trap,” where they observed a noteworthy phenomenon: gamma rays changing their position depending on the energy level.
High-energy gamma rays were discovered at the location where the jet flows appear again, indicating an effective acceleration of particles. Researchers simulated energy patterns and estimated the speed of external jets, finding a strong shock at the outer edge of the jet. This shock explains the reappearance of X-rays and the production of high-energy gamma photons.
While there is still much to learn, understanding SS 433 jets can help solve puzzles about larger jets from galaxies and quasars.
