At the very center of the supermassive black hole in the heart of our galaxy are two massive bubbles of extremely hot gas extending from the core of the Milky Way into near-galactic space. The point is, no one knows if the black hole is the source of their energy, or if it is something else. New observations, however, give more details about the formation of these bubbles and may help astronomers to pinpoint what is happening.
Gas bubbles were first observed because they emit ultra-high-energy gamma rays which are the highest energy form of light. These were mapped by NASA’s Fermi Observatory and received the nickname Fermi Bubble. These features are LotsA few thousand light years in size and so big They extend across two-thirds of the sky visible from Earth.
It’s incredible. We are 26,000 light-years from the center of the galaxy, but these structures are so huge that they cover a significant portion of our sky. However, they do not emit any visible light known to us, so we cannot see them with our eyes.
These are seen as bubbles, thin-walled structures filled with hot gas. However, the hot gas itself cannot produce gamma rays. Perhaps as strong as the plow of the gas flows in the thin material floating almost outside our strong exterior, so is the strong magnetic field locked with the gas; Together they can accelerate subatomic particles to incredibly high energies, enabling them to ferment gamma rays.
These bubbles have also been seen in radio waves, possibly due to magnetic fields. And now new observations show that they are also fully filled with X-ray emitted gas and they Bigger.
These observations were made by Erosita, an imaging telescope array, with the help of a German / Russian space-based observatory that could detect X-rays and augmented roentgen studies. This is a survey material, meaning it looks at the vast expanse of the sky to see what is happening on large scales.
Looking at the medium-sized X-rays of the whole sky, what it saw was:
We were loaded with dense dust inside the plane of the flat disc of the Milky Way, so we could see the silhouette across the entire center. You can see that the huge lobes are emitting X-rays and extending away from the upper and lower galactic centers of the galaxy, and they look as horrible as Fermi bubbles. Surprisingly, however, at 55,000 light-years they are even larger.
Erosita (Tille) and Fermi (red) bubbles are encouraged together here to show you the scale:
The bubbles seen by Erosita seem to me more like shells in contrast to the gas filling. Something filled with gas looks more solid, filled in, while a thin shell looks like something like a soap bubble or a ring in place. We see that when stars die for the formation of planetary nebulae.
It amazes me that if the erosita structures are the expanded front part of the gas that eases towards the material outside the galaxy and it is pucked like an ice plow, then Fermi bubbles start to expand the gas behind that front and fill the cavities left behind them. Hmmm.
To give you a better picture, here is a planner of what’s going on:
Purple gamma-rays show Fermi bubbles and yellow is seen by erosita on X-rays. The blue spirals represent the spiral arms of the Milky Way, the position of the Sun being noted. Astronomers use parsecs for some distance and KPC is 1000 parsecs. This equates to 3,260 light-years and the galactic disk spans about 120,000 light-years.
Yes, these structures are being reversed Lots. At such scales, the energy required for a gas explosion from a galaxy is mind-numbing. It is the same on X-rays only 100,000 supernovae. It looks like it happened about 20 million years ago.
What happened then? Did 100,000 huge stars explode?
Maybe better. Yes, seriously, that can happen. There has been an explosion of star formation in our galaxy, and there is some evidence that Fermi bubbles have burst by something like this. Huge cracks in the formation of stars make them so large that they can explode, and some observations point to the cause.
Sitting right in the middle of the galaxy, on the other hand, is a large black hole called SGR A * (literally “Sagittarius A-Star”). The gas falling into the black hole forms a huge disk that is incredibly hot and as it rotates around its magnetic field it turns into two huge cone-shaped rotating shapes that can explode at tremendous speeds outside the galaxy.
Our supermassive black hole is silent at the moment, but who knows millions of years ago? Perhaps huge clouds of gas and dust fell into it and caused an epic explosion that created erosita and fermy bubbles. All the stars in the galaxy come together in a burst of energy involved and become the Milky Way for a short time. Kosar.
One small problem with all of this is duration. According to Aerociter data it occurred 20 million years ago, but other observations show that it was probably 3 million years ago. These are not necessarily inconsistent; Ages like this can be hard to find. There’s a lot of uncertainty, with a whole bunch of things that can throw off assumptions.
But this is all good! These ridiculously huge sized features are still quite mysterious and hard to observe Because Their huge size. It takes a fairly all-sky survey to see these, let alone get an idea of their detailed structure. We have seen these in gamma rays and radio waves and now in X-rays. The more ways we look at them, the better we understand them … and the fact that they happened at the center of the galaxy is a huge event.