March 07, 2013

Colossal Bubbles at Milky Way’s Plane –”May Be the Annihilation of Dark Matter

n 2011, an analysis of data from a NASA Fermi Gamma-Ray Space Telescope turned up massive, previously unseen galactic structures. A group of astrophysicists located two massive bubbles of plasma, now know as “Fermi Bubbles,” each extending tens of thousands of light-years, emitting high-energy radiation above and below the plane of the galaxy. The structure spans more than half of the visible sky, from the constellation Virgo to the constellation Grus, and it may be millions of years old.

Now, more recently, in 2013, astrophysicists Dan Hooper of Fermi National Accelerator Laboratory and Tracy Slatyer at Princeton University, have published a study suggesting that a massive outflow of charged particles from Fermi bubbles, as they are known, outflows of charged particles (gamma rays) traveling at nearly a third the speed of light from the center of the Milky Way galaxy, may be partly due to collisions between dark matter particles that result in their annihilation, and the subsequent creation of the building blocks of visible matter—charged particles that appear as two lobes or “bubbles,” above and below the center of the Milky Way Galaxy.

Another possibility includes a particle jet from the supermassive black hole at the galactic center. In many other galaxies, astronomers see fast particle jets powered by matter falling toward a central black hole. While there is no evidence the Milky Way’s black hole has such a jet today, it may have in the past. The bubbles also may have formed as a result of gas outflows from a burst of star formation, perhaps the one that produced many massive star clusters in the Milky Way’s center several million years ago.

“In other galaxies, we see that starbursts can drive enormous gas outflows,” said David Spergel, a scientist at Princeton University in New Jersey. “Whatever the energy source behind these huge bubbles may be, it is connected to many deep questions in astrophysics.”

Read more: Colossal Bubbles at Milky Way's Plane –"May Be the Annihilation of Dark Matter" — The Daily Galaxy.

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