Us astrophysicists love a good unsolved mystery - because when you can’t explain something you’ve observed you know that eventually you’ll learn something new about the Universe.
Now one of the biggest unsolved mysteries still in astrophysics is dark matter - matter that doesn’t interact with light at all, but does with gravity so that we know it’s there. In the same way we can’t see the wind, but know that its windy because we can see the trees move. There has been a pile of evidence growing over the past century in favour of dark matter, and yet we still don’t know what its made of.
So while the particle physicists are fiddling with their big particle colliders trying to make or detect some dark matter, us astrophysicists are also constantly looking for new ways to detect it out in the universe and test if its there. The problem comes when you end up with another unsolved mystery in the process, like the Galactic Centre GeV excess - an as yet unexplained surplus of gamma rays, the highest energy light there is, that’s was discovered right at the centre of the Milky Way back in 2007.
And what’s exciting is this could be a signal that there’s a surplus of dark matter at the centre of the Milky Way, which would make it the first direct detection of dark matter. But this gamma ray excess could also be something else entirely, and not actually to do with dark matter at all...
00:00 - Introduction
03:16 - What is the Galactic Centre GeV excess?
06:33 - Dark matter annihilation explanation
10:26 - Milli-second pulsars explanation
13:32 - How will we figure out which is the right explanation?
15:48 - Bloopers