Mark Megahan
Sagittarius A lurks in what astronomers like to call the “Galactic Center” region of our Milky Way Galaxy. Here on planet Earth, “far out in the uncharted backwaters of the unfashionable end of the western spiral arm,” we don’t pay much attention to the super-massive black hole in the middle. Experts do, but even they didn’t know about one strange “structure extending north and south of our galactic center,” until now.
Astronomers are astounded
Astronomers with NASA and similar organizations around the planet have been “scouring our galaxy and beyond for decades.” Along with Exo-planets, they look for new celestial bodies and features of all sorts.
Every time they find one, it seems to muck up everything they thought they understood. A Chinese team just upset the astronomical apple cart when they noticed a cluster of extra gamma-rays.
A team at Chinese Academy of Sciences in Nanjing were taking a close look at “a map of radioactive gamma-rays that exist in and around the center of our galaxy.” They found hidden treasure in the form of “something near the center of the galaxy creating an abundance of cosmic rays and gamma-rays.”
Astronomers explain that “gamma-rays are the highest-energy form of light in the universe and come about when high-speed particles called cosmic rays slam into ordinary matter.” These particular super-intensity death rays are doing freaky things which scientists don’t quite understand.
According to the Chinese astronomers, “there is something preventing a large number of cosmic rays from entering from other parts of the universe.” Acting like an “invisible barrier,” the shield “wraps around the center and is causing the density of cosmic rays to be far less than the rest of our galaxy.”
The really strange part is that it’s a one way arrangement. “It seems cosmic rays are welcome to leave, but are having a hard time gaining entry.” Sort of like the opposite of the Eagles’ Hotel California where getting in is easy but leaving is the hard part. At the galactic center, once cosmic rays check out, they can’t come back.
Giant gamma-ray bubbles
The Fermi data image shows “giant gamma-ray bubbles emitting from the center of the galaxy” and has been making the rounds between astronomers since 2010. We’re sitting about 26,000 light-years from the black hole in the galactic center.
As the center of a city has more people per mile than out in the farmland, the dense galactic core is “home to more than 1 million times as many stars per cubic light-year” as the rest of the galaxy combined. The engine driving our galaxy, Sagittarius A, is a huge black hole with “a mass 4 million times that of the sun.”
Until now, all the astronomers were convinced that “Sagittarius A, or another object in the same area, has been creating cosmic rays that emit throughout the galaxy.” Creating a veritable sea of cosmic rays which permeates through the magnetic fields of our galaxy.
Data from the Fermi Large Area Telescope led researchers to confirm “that there is something located in the galactic center acting as an extremely large particle accelerator.”
The newly discovered shield itself has been frustrating astronomers because the barrier itself “is proving much harder to pinpoint its origin.”
The latest best guess is “it may involve the jumble of magnetic fields near the dense core of our galaxy.” They’re still working on figuring it out though. “Research is ongoing and, as more is discovered, it will either aid in uncovering the beginning of this invisible barrier, or simply spur more questions that need to be answered.”
One Comment