The Milky Way is blowing huge, mysterious bubbles that stretch for tens of thousands of light years
WHAT COULD HAVE CREATED THE BUBBLES? THE THEORIES SO FAR
There are a number of theories attempting to explain why the Milky Way is blowing these enormous bubbles.
Some scientists believe they could have been created by huge jets of accelerated matter blasting out from the supermassive black hole at the centre of our galaxy.
Or they could have been formed by a population of giant stars, born from the plentiful gas surrounding the black hole, all exploding as supernovae at roughly the same time.
Another theory is that they are the result of collisions between dark matter particles that result in their annihilation, emitting charged particles in the process.
‘There are several models that explain them, but none of the models is perfect,’ said Dmitry Malyshev, a postdoctoral researcher at the Kavli Institute.
A giant gamma-ray structure was discovered by processing Fermi all-sky data at energies from 1 to 10 billion electron volts, shown here. The dumbbell-shaped feature (centre) emerges from the galactic core and extends 50 degrees north and south from the plane of the Milky Way, in the sky from the constellation Virgo
Dmitry Malyshev, at the Kavli Institute for Particle Astrophysics and Cosmology in Stanford, found that the bubbles have very clear outlines and are fixed at each pole of the Milky Way.
The bubbles themselves, he claims, glow in nearly uniform gamma rays and appear like two 30,000-light-year-tall incandescent bulbs screwed into the centre of the galaxy.
But according to current astrophysical theories, these gamma rays shouldn’t be there, and scientists have been unable to find a source.