Astronomers observe the innermost structure of a quasar jet


An international team of scientists has observed for the first time the narrowing of a quasar jet using a network of radio telescopes around the world.

The results suggest that the narrowing of the jet is independent of the level of activity of the galaxy that launched it.

Almost all galaxies harbor a supermassive black hole at their center. In some cases, the gas falling towards the black hole releases enormous amounts of energy, creating a phenomenon known as a quasar. Quasars emit narrow, collimated jets of material at nearly the speed of light. But how and where the quasar jets collimate has been an old mystery.

An international team led by Hiroki Okino, a graduate student at the University of Tokyo, and comprising members of the National Astronomical Observatory of Japan (NAOJ), the Massachusetts Institute of Technology, Kogakuin University, Hachinohe National College of Technology and Niigata University, captured an image with the highest angular resolution to date that shows the deepest part of the jet in a bright quasar known as 3C 273.

The team discovered that the quasar’s flowing jet narrows over a very long distance. This narrowing part of the jet continues incredibly far, far beyond the area where the black hole’s gravity dominates, reports the NAOJ in a statement.

The results show that the structure of the jet is similar to jets launched from nearby galaxies with a low-luminosity active nucleus. This would indicate that the collimation of the jet is independent of the level of activity in the host galaxy, providing an important clue to unravel the inner workings of the jets.

The research has been published in The Astrophysical Journal on November 22, 2022.