Abstract
The Geminga pulsar has long been one of the most intriguing MeV-GeV -ray point sources. We examine the implications of the recent Milagro -ray Observatory detection of extended, multi-TeV -ray emission from Geminga, finding that this reveals the existence of an ancient, powerful cosmic-ray accelerator that can plausibly account for the multi-GeV positron excess that has evaded explanation. We explore a number of testable predictions for -ray and electron or positron experiments (up to ) that can confirm the first “direct” detection of a cosmic-ray source.
- Received 30 October 2008
DOI:https://doi.org/10.1103/PhysRevLett.103.051101
©2009 American Physical Society