When the universe was a tiny billion years old, a galaxy spewed out a huge jet of rapidly moving radiation and plasma into the cosmos. Almost 13 billion years later, this jet is visible to humans in the form of a blazar. The jet was recently photographed and analyzed by a team of Italian astronomers. Their results, which give an idea of the length and speed of the jet, were recently published in the journal Astronomie et astrophysique.
View through the Very Long Baseline Matrix — A formation of 10 radio telescope antennas stretching from St. Croix in the Atlantic Ocean to Mauna Kea in Hawaii in the Pacific – the blazar looks like a galactic smear of sauce tomato on the cosmic lens. What is actually captured in the false-color image, however, is a bright orange plasma jet, pointed roughly at us and spanning about 1,600 light years, a distance that defies earth analogy.
According to Cristiana Spingola, astronomer at the University of Bologna and lead author of the recent article, scientists don’t see as many blazars as you might expect in the early universe.
“Among the different scenarios, this mismatch could be due to the fact that distant blazars have different properties because the local population of blazars, as the jet moves slower than what happens locally,” Spingola wrote in an e- mail. “That’s what our results suggest. If this were confirmed, we would have found that local and distant blazars are different beasts.
Such jets are emitted from the centers of galaxies by supermassive black holes. Black holes accumulate discs of matter around them, sometimes ejecting jets of matter outward at extraordinary speed. These galactic centers, called active galactic nuclei, are all known as quasars; when the beams they eject are directed towards us, they are called blazars.
A few years ago, the blazars proved to be the sources of ultra-high energy cosmic rays, transforming them from an object of intrigue into a compelling source of information about the early universe. First detected in March 2020, the recently described blazar named PSO J030947.49 + 271757.31 (luckily abbreviated as PSO J0309 + 27) is located in the constellation Aries, about 12.8 billion light years away. of the earth. The blazar is the brightest in radio waves and the second brightest in X-rays among those from when the Universe was less than a billion years old. It is also the most distant galaxy from us ever to eject such a jet, which also makes it the oldest blazar ever observed.
“These properties make it an ideal object to study [active galactic nuclei] at cosmological distances, ”Spingola wrote. “We know very little about the young Universe, so any new information is crucial to better understand this era.”
The team discovered that the blazar jet was moving at three-quarters the speed of light; an extraordinary pace, but not the fastest, as other blazars have been recorded at over 90% the speed of light.
The pretty streak you see is actually an image made by integrating three different observations of the jet, taken at different radio frequencies, to obtain structures of the jet invisible on the others. All in all, the image shows a blazar jet extending upward into the empty darkness, with its brightest section towards the bottom, where the core of the blazar is located.