NASA's Imaging X-ray Polarimetry Explorer (IXPE), in collaboration with the Italian Space Agency (ASI), has achieved a breakthrough in understanding X-ray production in extreme environments like black hole jets. By observing the blazar BL Lacertae, a supermassive black hole with jets pointed towards Earth, IXPE data reveals that X-rays emitted from these jets originate from electrons.
Discovery Details
During a seven-day observation in November 2023, IXPE, along with ground-based telescopes, measured optical and radio polarization. The data indicated that electrons are the primary source of X-rays through a process called Compton scattering. In this process, electrons moving at near-light speed collide with photons, boosting the photons to X-ray energies.
Why It Matters
This finding resolves a long-standing debate about whether X-rays in blazar jets are produced by protons or electrons. The discovery provides critical insights into the physical processes within supermassive black hole jets, influencing galaxy dynamics and multi-wavelength radiation emission. IXPE, launched on December 9, 2021, is uniquely capable of measuring X-ray polarization, making it instrumental in this and future studies of extreme cosmic objects.