Presentation #110.08 in the session “Stellar/Compact (Poster)”.
We present new X-ray and optical observations of the remarkable filament and bow shock of Gamma-ray pulsar PSR J2030+4415. Over the past decade a handful of X-ray pulsar filaments have been discovered, characterized by their substantial angle to the pulsar velocity vector, large extent and one-sided domination. These filaments are potentially of importance to high energy astrophysics, since they are thought to indicate rapid anisotropic propagation of multi-TeV cosmic ray leptons many parsecs from the pulsar generation sites. As such they may help us understand the anomalous positron excess in the local cosmic rays.
J2030 has an associated Hα bow shock and our new images trace its evolution over the past decade. Comparing with the Hα velocity structure we derive an improved kinematic distance of ~0.5 kpc. These velocities also imply that the pulsar spin axis lies ~15° from the proper motion axis which is close to the plane of the sky. The multi-bubble shock structure implies that the shock stand-off was compressed to a small value ~20–30 years ago when the pulsar broke through the bow shock to its present bubble. This compression allowed multi-TeV pulsar e± to escape to the eternal ISM over a period of several years, lighting up an external magnetic field structure as the ‘filament’.
The new X-ray observations reveal that the filament extends at least 15' (2.2pc), indicating rapid e± propagation to its end. The filament flux remains constant or even increases along its length, while the filament width increases linearly, likely as a consequence of diffusion. To reconcile these properties, we suggest a picture in which the particle injection rate is high at breakthrough and then tapers off as the stand-off distance grows back toward pre-breakthrough scale. Alternatively, if the particle injection were continuous, we would expect the filament to follow the pulsar proper motion, shifting ahead of its current leading edge. Future CXO observations could discriminate between these models.