Milky Way's first microblazar may produce fastest particles in the galaxy

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: An international team of astronomers from ASTRON, JIVE, the University of Amsterdam and other institutions has found the first so-called "microblazar" in the Milky Way. This stellar system is composed of a massive star and a black hole with a jet that is pointed toward Earth.

The researchers also identified the region where the jet hits a molecular cloud as a place where particles are accelerated to ultra-high energies, likely up to petaelectronvolts. This would make microblazars one of the most powerful particle accelerators in the galaxy. The research was appears in Astronomy & Astrophysics.

Black holes can attract matter from their surroundings, powering jets of matter and radiation that escape from their poles with extremely high energies. When such a jet is pointed toward Earth, it makes the object appear much brighter. In the case of supermassive black holes—which are found at the center of many galaxies—such blazars have been studied for a long time.

Now, for the first time, astronomers have identified a stellar-sized black hole in the Milky Way whose jet is pointed toward Earth. It is the first microblazar found. Radio imaging has revealed not only the jet but also its interaction with its surroundings.

First, the jet crosses a region of about 100 light-years (590 trillion miles), where it has already "cleared" the so-called interstellar medium. After that, it hits a relatively dense molecular cloud, which consists mainly of molecular hydrogen and dust. The interaction creates a bright spot on the cloud where the interstellar material is ionized and the dust is heated.

Here, particles are accelerated to nearly the speed of light, with energies up to petaelectronvolts. This makes the microblazar one of the most powerful particle accelerators in the Milky Way, about 100 times stronger than the Large Hadron Collider, the strongest particle accelerator on Earth. Microblazars have been predicted for about 30 years.