The Long Filament of PSR J2030+4415

Abstract

New X-ray and optical observations shed light on the remarkable X-ray filament of the Gamma-ray pulsar PSR~J2030+4415. Images of the associated H$\alpha$ bow shock's evolution over the past decade compared with its velocity structure provide an improved kinematic distance of $\sim$0.5kpc. These velocities also imply that the pulsar spin axis lies $\sim 15^\circ$ from the proper motion axis which is close to the plane of the sky. The multi-bubble shock structure indicates that the bow shock stand-off was compressed to a small value $\sim 20-30$y ago when the pulsar broke through the bow shock to its present bubble. This compression allowed multi-TeV pulsar $e^\pm$ to escape to the external ISM, lighting up an external magnetic field structure as the `filament'. The narrow filament indicates excellent initial confinement and the full $15^\prime$ ($2.2$~pc=7~lt-y) projected length of the filament indicates rapid $e^\pm$ propagation to its end. Spectral variation along the filament suggests that the injected particle energy evolved during the break-through event.