AMS02 results support the secondary origin of cosmic ray positrons

We show that the recent AMS02
positron fraction measurement is perfectly consistent with a secondary origin for positrons, and does not require additional primary sources such as pulsars or dark matter. Within the secondary model the AMS02 data imply a cosmic ray propagation time in the

Galaxy of about one Myr and an average traversed interstellar matter density of about 1/cc at a rigidity of 300 GV. These results may hint that high energy cosmic rays are confined to a thin halo of scale height similar to the gaseous disk.

Event Type: 
Scientific Area(s): 
Event Date: 
Friday, May 3, 2013 - 13:00 to 14:30
Space Room