The scientists looked at a strange phenomenon called a blazar that was located at the core of a massive elliptical galaxy.
White House: Huge black holes are the foundation of the majority of galaxies. While many of them are relatively calm, like the one at the center of our Milky Way, some are fierce, gobbling up the nearby matter and ejecting enormous, brilliant jets of high-energy particles into the far reaches of space.
Researchers proposed an explanation for how these jets became so bright on Wednesday using data from the recently deployed Imaging X-ray Polarimetry Explorer (IXPE) orbiting observatory: shock waves traveling at supersonic speed away from the black hole energized subatomic particles called electrons.
The scientists looked at a strange object known as a blazar at the heart of a massive elliptical galaxy called Markarian 501, which is about 460 million light-years from Earth and faces the constellation, Hercules. 5.9 trillion miles is the distance that light travels in a year or a “light year.”
Blazars are a subset of quasars, which are powered by supermassive black holes at the galactic center that eat gas and other matter while ejecting two jets of particles into space in opposite directions. Blazars are positioned so that one of their two jets is pointed directly at us from where we are standing on Earth.
As the lead author of the study that was published in the journal Nature, astronomer Yannis Liodakis of the Finnish Centre for Astronomy with ESO said, “Blazars are the most persistently bright objects in the observable universe. They are the most energetic. They have the biggest, scariest black holes.
The behavior of the particles in blazar jets and how they grow so bright has long been a mystery to scientists. This blazar’s jets can be seen from approximately one million light years away.
IXPE, a joint project of NASA and the Italian Space Agency, was launched last December and monitors the brightness and polarisation of X-ray light coming from cosmic sources. Polarization is a feature of the light involving the orientation of electromagnetic waves. Different processes, including shock waves and turbulence, exhibit “signatures” of polarization.
According to scientists, when a shock wave traveling outward inside the stream strikes a particle in the jet, it energizes it and causes it to accelerate, emitting X-rays. When something travels faster than the speed of sound through a medium like air, as a supersonic jet does as it flies through the Earth’s atmosphere, or a region with particles and magnetic fields called plasma, as in this situation, a shock wave is created.
“The light that we see from the jets comes from electrons,” says co-author of the paper and astrophysicist at Boston University Alan Marscher. The only source of the kind of X-rays we see in Markarian 501 is extremely high-energy electrons.
A black hole, an incredibly dense object whose gravity is so strong that not even light can escape, is the driving force behind this drama. Markarian 501’s supermassive black hole has a mass that is roughly a billion times that of the sun. That is almost 200 times more massive than Sagittarius A*, the supermassive black hole at the center of the Milky Way.
According to Liodakis, “black holes are special laboratories to investigate fundamental physics under harsh settings we cannot recreate on Earth.”
“However, we must first comprehend all of the underlying physical processes in order to employ them as such.” We’ve been observing the high-energy light coming from those sources for a long time, and we’ve developed a few theories about how those light-emitting particles are fueled. “We were able to directly test our hypotheses for the first time because of IXPE’s X-ray polarisation capabilities,” explained Liodakis.