Scientists have finally found the secret mechanism behind the universe’s brightest light displays. This secret mechanism is powered by the absurdly energetic beams emitted from explosive galaxies called blazars.
This breakthrough was possible thanks to a new space mission, which can see for the first time the amazing physics that fuels these astrophysical Jets. These jets are made up of ultrafast particles that shine with the brightness that 100 billion Suns.
Our galaxy, the Milky Way is currently in a sleepy phase. However, other active galaxies are bursting with the energetic matter, which is being fueled by supermassive black hole centers. Radiant jets can erupt from these galaxies due to intense interactions between huge black holes and their gassy surrounding. Some jets reach depths of more than a million miles.
Blazars are active galaxies that have jets that directly point at Earth. These objects are millions to billions of light-years away so they pose no threat to Earth. However, their jets can still be seen even at such great distances. Astronomers have seen thousands of blazars, but no one has been able to identify the exact mechanisms that make them so bright.
Ioannis Liodakis is a Gruber Fellow at Finland’s Centre for Astronomy and the European Southern Observatory at the University of Turku. He was able to solve the mystery thanks to the Imaging X-ray Polarimetry Explorer IXPE. This mission, which was a joint mission by NASA and the Italian Space Agency, launched into orbit in December 2021.
Liodakis used IXPE with his colleagues to study Markarian 501, an extremely bright blazar that is more than 300 million light-years from Earth. IXPE, which is the first mission to capture a pattern called Polarization in X-ray light, allowed researchers to prove that these particles are supercharged with shock fronts. This solved a long-standing question about the dynamics and dynamics of these bright objects.
These sources have been known since the 60s, Liodakis stated in an email to Motherboard. He was referring to blazar planes. They are the most visible objects in X-rays, and we didn’t know for years how they were made. Although we had some theories, the radio and optical data that we could obtain were not able to give us much.
He explained that X-rays are closer to the accelerator site than those which come from far away. They allow us to see the acceleration region and the physical conditions, which makes them an ideal tool for answering our questions.
In other words, each band in the spectrum tells a different story, and scientists have missed the crucial X-ray chapter. Researchers have been trying to capture the polarization in X-rays from the jets. This is essentially a pattern embedded within the configuration of light waves that contain data about how and where the light was produced.
Although scientists have been studying the polarizations of blazar jets for decades in different light spectrum bands, IXPE is the only instrument that can see these patterns in high-energy X-ray light. This light illuminates the initial process which sends the jet particles into deep space at unimaginable energies. Liodakis stated that the mission had been on the wishlist for astronomers for decades. Its observations have allowed scientists to be able to observe and after all these years to directly test their models.”
IXPE’s March 2022 view of Markarian 501 shows that particles in a jet can be accelerated by colliding with slower-moving material in a galaxy. This creates a shock wave that spreads through the jet, boosting the particles to incredibly high levels of energy. The X-ray emission of particles that travel in this wave is highly polarized. As they move past it, the polarization decreases.
These results confirm the models that predicted the central function of shock waves in powering cosmic particle accelerators. They are natural laboratories for studying light and matter behavior at very high energies. Liodakis and colleagues hope that IXPE and other similar instruments will continue to reveal the secrets of blazars as well as their pyrotechnicjets, including Markarian 51.
Liodakis stated that our observations were made when Markarian501 was in an activity level of around average. These sources are always active but they can sometimes go into outbursts that can increase their brightness by more than 100x. These states are not covered by our findings.
He concluded that we have made additional observations and will be able to figure out what’s happening in the jets during these outbursts.