A Pulsar Alone
The closest known isolated radio pulsar also has one of the slowest rotation rates — far below what should be observable for a pulsar. This paper discusses X-ray and optical observations of this puzzling object.
Constraining the Energy of Cosmic Rays
Ultra-high energy cosmic rays may be produced via shock acceleration. This paper presents theoretical upper limits on the energies of the cosmic rays that can be produced in this way, providing a means of testing this theory.