First observation of X-ray flare “Kodama” coming from behind a black hole | sorae Portal site to space

On July 28, Stanford University in the United States, a research team led by Dan Wilkins, came from behind a supermassive black hole in the center of the galaxy, “Echo” of X-ray flare (echo）Announced that it succeeded in observing for the first time.

According to the research team, observing such echoes will deepen our understanding of the environment just outside the supermassive black hole.

[▲ Illustration (Credit: ESA) that explains the structure around the supermassive black hole in an easy-to-understand manner]

If there is gas around the supermassive black hole in the center of the galaxy, it will be swallowed by the supermassive black hole while swirling.This vortexAccretion diskIt’s called.

This accretion disk generates enormous heat due to friction between substances.Millions of °CDue to the high temperature, the substance is ionized into atomic nuclei and free electrons and turned into plasma.

Corona (Corona in the illustration)Exists above such an accretion disk.It is a very hot plasma cloud, and its temperature is from X-ray observations.About 1 billion ℃Is also being reached.

As for why the corona is so hot,Magnetic field generated by the accretion diskIs thought to be related, but the fact is that it is not well understood due to negative observations.

The research team originally came from a supermassive black hole in the center of a galaxy about 800 million light-years away from the earth to study the corona of such a mysterious supermassive black hole. I was observing (the rapid brightening phenomenon of X-rays produced by corona). Eventually, the research team, after the X-ray flare,Weaker, slower, “colors”) X-ray flashes with different “colors”I noticed that is continuing.

According to the research team, this X-ray flash is due to its characteristics that the X-ray flare produced by Corona hits the accretion disk behind the supermassive black hole and bounces off. In other words, it is an echo of X-ray flare that came from the back side of a supermassive black hole.

Originally, light (electromagnetic waves) such as X-rays behind the supermassive black hole should not be observed, but due to the powerful gravity of the supermassive black hole, it should not be observed as a result of the twisting of space-time. Things were observed. The correctness of Einstein’s general theory of relativity was proved here as well.

According to the research team, by observing the echoes bouncing off such an accretion disk,Event horizon (event horizon, the boundary where even light cannot come out)It is said that it can present a new perspective on the environment just outside.

Image Credit: Dan Wilkins＆ESA
Source: Stanford University Press Release / Treatise
Sentence / Shigeyuki Iido