[In an Air & Space museum]
Guide: Right this way, please.
Teacher: Stay in line children, we’re on our best behavior at the Earth Early Space Exploration Museum.
Guide: And here we have the life-sized recreation of the Fermi Gamma-ray Space Telescope which launched waaaay back in 2008.
Entoz: What does Fermi have to do with dark matter?
Guide: In the 20th century, Weakly Interacting Massive Particles, or WIMPs, were first hypothesized to be a form of dark matter.
Guide: In this theory, two WIMPs can annihilate each other, producing gamma rays. Because dark matter is spread out over vast but specific regions, like around galaxies, Fermi should see a continuous gamma-ray glow from dark matter regions.
Enotz: So, did Fermi detect this gamma-ray glow?
Alkina: Entoz! We learned about that last semester, you weren’t paying attention.
What does it mean?
Weakly Interacting Massive Particle (WIMP) – WIMPs are hypothesized sub-atomic particles that interact only through gravity and the weak force.
In human speak please!
We currently do not know what makes up dark matter, but one possibility is WIMPs. These heavy particles do not emit, absorb, nor reflect light. However, a WIMP can annihilate when it comes into contact with another WIMP. In the annihilation process the mass of the two WIMPs is converted to gamma rays. Dark matter can be more easily detected in regions where there is little to no normal matter (e.g. galactic halos) and we would expect to see a steady stream of gamma rays emanating from these regions if WIMPs exist due to their constant annihilation.
To date, Fermi has not detected the gamma-ray glow of annihilating WIMPs.
Is that all?
Dark matter detection. – A news article about how Fermi might detect dark matter.
Fermi Telescope Finds Giant Structure in our Galaxy – Although Fermi has not yet discovered dark matter, Fermi’s search for dark matter near the center of our Milky Way galaxy, led to the discovery of giant, gamma-ray emitting bubbles.