Home » News & Blogs » Should We Blame Pulsars for Too Much Antimatter?
Bookmark and Share
AAS Nova

Should We Blame Pulsars for Too Much Antimatter?

9 Oct 2019, 16:00 UTC
Should We Blame Pulsars for Too Much Antimatter?
(200 words excerpt, click title or image to see full post)

The Earth is constantly being bombarded by cosmic rays — high energy protons and atomic nuclei that speed through space at nearly the speed of light. Where do these energetic particles come from? A new study examines whether pulsars are the source of one particular cosmic-ray conundrum.
An Excess of Positrons
Artist’s impression of the shower of particles caused when a cosmic ray hits Earth’s upper atmosphere. [J. Yang/NSF]In 2008, our efforts to understand the origin of cosmic rays hit a snag: data from a detector called PAMELA showed that more high-energy positrons were reaching Earth in cosmic rays than theory predicted.
Positrons — the antimatter counterpart to electrons — are thought to be primarily produced by high-energy protons scattering off of particles within our galaxy. These interactions should produce decreasing numbers of positrons at higher energies — yet the data from PAMELA and other experiments show that positron numbers instead go up with increasing energy.
Something must be producing these extra high-energy positrons — but what?
Clues from Gamma-rays
One of the leading theories is that the excess positrons are produced by nearby pulsars — rapidly rotating, magnetized neutron stars. We know that pulsars gradually spin slower and slower ...

Latest Vodcast

Latest Podcast

Advertise PTTU

NASA Picture of the Day

Astronomy Picture of the Day

astronomy_pod