Say What? Astronomy

Source of blazars’ super brightness comes into focus

Jets of high-energy radiation come from near galaxies’ central black hole

JET SET An active galaxy called a blazar, illustrated here, emits a jet of high-energy particles toward Earth.

NASA/Goddard Space Flight Center Conceptual Image Lab

By Andrew Grant

July 14, 2015 at 12:30 pm

Blazar
BLEHY-zahr n.

An unusually luminous galaxy that fires off a jet of high-energy matter and radiation toward Earth.

Blazars have been spotted throughout the sky, but researchers don’t know how these jets form. Scientists suspect that gas piles up near a galaxy’s central black hole, where it heats up and gets flung away at nearly the speed of light. Astronomers are studying the blazar PKS 1830-211. Although it is about 11 billion light-years away, the gravity of at least one nearer galaxy acts as a lens, enabling scientists to examine the distant blazar’s energetic outbursts.

The source of high-energy gamma rays from PKS 1830-211 is a confined area about the size of the solar system, University of Geneva astrophysicist Andrii Neronov and colleagues report July 6 in Nature Physics. The finding confirms that whatever is driving blazar jets operates right near the central black hole, which can weigh in at millions or billions of times the mass of the sun.