A powerful vibration wave traveling through a galaxy left behind by an explosion of a star is of a different nature: Part of it is going in the wrong direction, new research shows.
In the study, the researchers found that a vibrating wave travels rapidly in a variety of ways, including a particle crashing into the base of a supernova, or supernova. author called it a “reversal.”
Cassiopeia A nebula, or galaxy, was deposited by a supernova in the constellation Cassiopeia, about 11,000 light -years from Earth, and became one of the closest supernova remnants. The nebula, which is about 16 light -years across, is made of gas (a large amount of hydrogen) that was expelled before the first star exploded. The vibration wave from that explosion is moving through the gas, and examples have shown that this vibration wave needs to be amplified, just as a circular balloon needs to be amplified.
But researchers know this is not the case.
“For a long time, we thought something else was going on in Cassiopeia A,” lead author Jacco Vink, an astronomer at the University of Amsterdam in the Netherlands, told Live Science. Preliminary studies have shown that the movements in the nebula are “chaotic” and have shown that the western side of the vibration wave moving in the galaxy may be wrong, he said.
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In the new research, researchers analyzed the motion of the vibrating wave, using X-ray images collected by NASA’s Chandra X-ray Observatory, a telescope that orbits the Earth. Earth. The data, collected over 19 years, confirms that the western part of the tsunami is, in fact, returning to the other side to a post -earthquake.
But they also saw something else amazing: Parts of the same planet are moving fast from the epicenter of the supernova, like the rest of a tremor wave.
Various additions
The current average speed of the gas rising in Cassiopeia A is about 13.4 million mph (21.6 million kph), which is one of the fastest shaking waves seen in a supernova remnant, Vink said. This is important for the youngest remnant; Light from Cassiopeia A arrived on Earth in 1970. But over time, the shaking waves lost their places and slowed down.
Cassiopeia A is in two major gas groups: the inner shell and the outer shell. These two shells are two parts of the same vibration wave, and in most nebulae, the inner and outer shells travel at the same speed and in the same direction. But in the western hemisphere, the two sides go in opposite directions: the outer surface is constantly expanding, but the inner surface is moving to where the star explodes.
The rear vibration decreases at about 4.3 million mph (6.9 million kph), which is one -third of the average speed of the rest of the nebula. However, what surprised the researchers the most was how quickly the outer shell grew compared to the inner skin in this area. The researchers thought that the outer surface would increase at a lower rate compared to the rest of the vibration wave, but they found that the speed was much faster than some parts of the vibration wave. “It was absolutely amazing,” Vink said.
Earthquake
The magnitude of the difference in the western land of Cassiopeia A is not consistent with the theoretical supernova phenomena and it has been shown that something is found in the tremor wave behind the star crater, Vink said.
The researchers said that the best explanation for the shock wave was to report to a mass of gas released by a star before it exploded. When the vibrating wave hits this gas, it may slow down and make a stirring to return the inner shell to its center. However, the outer skin may have been attached to this pad and started to speed up again on that side, said Vink. “This explains how the inside of the shell moves inside but also predicts that the outer skin will move faster, as we measured,” he said.
Researchers believe that the unique way in which the star star died could explain the various vibration waves. Cassiopeia A is the result of a Type IIb supernova, where a large star exploded after it melted its outer layers, Vink said.
“X-ray estimates show that the sun’s star was four or six times larger at the time of the explosion,” Vink said, but the star was about 18 times larger. the day of his birth. That is, the star lost about two -thirds of its mass, most of which was hydrogen, before it exploded; The shock wave may have been connected with this gas, Vink said.
There are many speculations as to why Cassiopeia A disappeared so much before the explosion. In September 2020, a group of researchers thought that the primary star was part of a binary star system, where two stars glide at each other. That research team said that this companion star could travel to a supernova before Cassiopeia A and destroy the star’s hydrogen “skin” in the process. Live Science was first shown (opens on new page).
However, the authors of the new study are not clear on this concept. “The only problem is we don’t see the rest of the other star,” Vink said. “So right now, speculative continues.”
So far, no one knows exactly what triggers Cassiopeia A’s various vibration waves.
The study was published online Jan. 21 in the preprint server arXiv (opens on new page) and has been approved for future publication in The Astrophysical Journal.
Originally published on Live Science.
