Cosmic ray positrons from a local, middle-aged supernova remnant

TL;DR

This paper proposes that the excess of cosmic ray positrons observed by multiple experiments can be explained by production in a nearby, middle-aged supernova remnant, likely the one that created the Geminga pulsar.

Contribution

The study introduces a model linking cosmic ray positron excess to a specific local supernova remnant, estimating its distance, age, and potential identity.

Findings

The positron excess is consistent with a supernova remnant 250-320pc away, 170-380kyr old.

The Geminga remnant is the most probable source of the positron excess.

Other potential remnants are also considered as sources.

Abstract

We argue that the cosmic ray positron excess observed in ATIC-2, Fermi LAT, PAMELA, HESS and recently in the precision AMS-02 experiment can be attributed to the production in a local, middle-aged supernova remnant (SNR). Using the prediction of our model of cosmic ray acceleration in SNR we estimate that the SNR responsible for the observed positron excess is located between 250 and 320pc from the Sun and is 170-380 kyear old. The most probable candidate for such a source is the SNR which gave birth to the well-known Geminga pulsar, but is no longer visible. Other contenders are also discussed.