A thing that doesn’t emit light We can detect it, Black holesIt is a joy to be radiant.
Supermassive black hole are responsible for some of the most brilliant light in the Universe. Actually, it’s not actually the black hole itself; it’s their surrounding material as they actively slurp up vast quantities of matter from their immediate surroundings.
Galaxies called blazars are some of the brightest among these swirling hot material maelstroms. They not only glow with the heat of a swirling coating, but they also channel material to ‘blazing beams, which zoom through the cosmos, emitting electromagnetic radiation at energies difficult to understand.
Scientists finally have a mechanism to produce the amazing high-energy light that reached us billions of years back. Black holeJets that increase the speed of particles to mind-blowing speeds
“This is an old mystery, 40 years old that we have solved,” says astronomer Yannis LiodakisFinnish Centre for Astronomy and ESO (FINCA). “We finally had all the pieces to the puzzle and the picture they made was crystal clear.”
The supermassive black holes are the center of most galaxies in Universe. These massive objects, which are sometimes very small, sit in the galactic centre. Sagittarius A*The black hole in the center of the Milky Way), and sometimes doing a lot.
This activity is made up of accreting materials. A huge cloud forms around the black hole and circles it like a circle. Water around a drain. This material heats up due to the frictional and gravitational interactions that take place in extreme space around a black hole. It then shines brightly at a variety of wavelengths. This is one source of the black hole’s light.
The other – the one at play in blazars – are twin jets of material launched from the polar regions outside the black hole, perpendicular to the disk. These jets are material from the inner edge of the disk, which, instead of falling towards the black hole, is accelerated along the external magnetic field lines to reach the poles. It then launches at high speeds, very close to the speed light.
To be classified as a Blazar Galaxy, the jets must be almost pointed at the viewer. We are Earth. Extreme particle acceleration allows them to shine with light across the electromagnetic spectrum including high-energy Gamma- and High-energy X-rays.
Since the beginning of time, scientists have been trying to figure out how this jet propels the particles at such high speeds. The Imaging X-ray Polarimetry Explorer is a powerful new X-ray telescope.IXPEThe key to solving the mystery was provided by the launch of the ) in December 2021. It’s the world’s first space telescope to determine the orientation (or polarization) of Xrays.
“The first Xray polarization measurements of the class of sources allowed, first time, a direct comparision with the models created from observing other frequencies light, from radio to very-high-energy gamma rays.” says astronomer Immacolata DonnarummaItalian Space Agency.
IXPE was turned on the Brightest high-energy objectA blazar called Markarian501 is located in our sky at 460 million miles away in the constellation Hercules. The telescope recorded data for six days on March 2022 about the X-ray light emitted from the jet of the Blazar.
Other observatories were also measuring light from other wavelengths, including radio and optical. These data were previously unavailable for Markarian 501.
The team soon noticed an interesting difference in the Xray radiation. It had a significantly different orientation to the lower-energy wavelengths. It was also more polarized then the radio frequencies.
The polarization direction was consistent for all wavelengths, and it aligned with that of the jet. The team concluded that this was consistent with models inwhich shocks in jets generate shockwaves that add acceleration along the lengths of the jet. This acceleration produces X-radiation at its greatest close to the shock. The particles move further along the jet and lose energy. This results in lower-energy optical, then radio emission, and lower polarization.
“As shock waves cross the region, the magnetic fields gets stronger and the energy of particles gets greater.” says astronomer Alan MarscherBoston University. “The shock wave energy is generated by the motion energy in the material.”
Although it is not known what causes the shocks, one possibility is that faster material in the jet may catch up to slower-moving particles, causing collisions. Future research may confirm this hypothesis.
This research is a significant piece of the puzzle, as blazars are one of the most powerful particle accelerators anywhere in the Universe.
Future research will continue to monitor Markarian 501 and to turn IXPE on other blazars in order to determine if similar Polarization can be detected.
The research was published in Astronomy of Nature.
