Feed the extreme jets of active galaxies

An active galaxy nucleus (AGN) contains a supermassive black hole that is a material that accumulates vigorously. It usually ejects jets of particles that move at a speed close to that of light, radiating on many wavelengths, especially X-rays. Processes are among the most energetic phenomena in the world. ;universe. The jets are often very strongly collimated and extend far beyond their host galaxy. If they are in the line of fire, they constitute the most spectacular class of this phenomenon: the blazars.

A few years ago, astronomers noticed that certain types of blazars have a jet power that seems to exceed that provided by the accumulation. Two ideas have been put forward to explain the difference: the jets also extract energy from the spin of the black hole or the magnetic flux around the object. There is a lot of discussion about how one or the other process happens, but a popular argument is that the processes are in some way related to the mass of the supermassive black hole, with the most massive cases (more than a hundred millions of masses) being the most abnormal. Recently, the Fermi gamma ray telescope has detected gamma rays (even more energetic photons than X-rays) from jets belonging to a class of galaxies called Seyferts, spiral galaxies with relatively small masses of supermassive black holes. , usually about ten million solar masses. . Astronomers have hypothesized that these relatively weak and yet powerful mass-emitting engines could provide keys to sort the different power sources of the jets.

Mislav Balokovic, CfA astronomer, and his colleagues completed a multi-length wave study of the brilliant blazar-like Seyfert galaxy, PKSJ1222 + 0413, and included gamma ray data on the radio, both archive and new observations, including new results from the NuSTAR space observatory. They then undertook a complete modeling of this source, the furthest away from this known type: its light has been moving towards us for about eight billion years. They detected the pronounced signature of an accretion disk and estimated that the supermassive black hole mass of the widths and forces of the emission lines was about two hundred million masses. about ten times greater than most other Seyferts of this type. The brightness of the jet represents only about half of the brightness of the accretion, unlike galaxies whose jet power exceeds accretion. Nevertheless, the object clearly falls into a transition regime for jet forces, allowing future studies to study in more detail the origins of jet power, both in Seyfert's galaxies and in blazars.