NASA's IXPE Solves Black Hole Jets Mystery with New Observations

An international team of astronomers using NASA's IXPE, the Imaging X-ray Polarimetry Explorer, has resolved the origins of X-rays in the jet of a supermassive black hole, a mystery that has persisted since the inception of X-ray astronomy.

Their findings, detailed in a paper published in The Astrophysical Journal Letters on November 11, stem from IXPE's longest observation of a single target, lasting over 600 hours across 60 days from January to March, focusing on the Perseus Cluster.

The scientists concentrated on the polarization properties of 3C 84, an active galaxy at the cluster's center, which is a prominent X-ray source due to its proximity and brightness. The observatory utilized combined data from NASA's Chandra X-ray Observatory, Nuclear Spectroscopic Telescope Array, and Neil Gehrels Swift Observatory to confirm measurements of the galaxy cluster.

IXPE's polarization measurements reveal that X-rays from active galaxies like 3C 84 are primarily emitted through a process known as inverse Compton scattering. This occurs when light interacts with particles and gains energy, with polarization levels providing insights into the alignment of emitted X-ray light waves.

The IXPE observations indicated a net polarization of four percent in the X-ray spectrum, a result that aligns with predictions from the synchrotron self-Compton model, as opposed to the external Compton model, which suggests a different origin for the seed photons.

Scientists, including project scientist Steven Ehlert and lead author Ioannis Liodakis, emphasized the importance of these findings in enhancing our understanding of black hole jets and high-energy astrophysics.

The IXPE mission, led by NASA's Marshall Space Flight Center, continues to deliver groundbreaking discoveries with contributions from the Italian Space Agency and partners across twelve countries. For further information, visit NASA's IXPE webpage.