Large scale X-ray jets from hyper-fast runaway pulsars -- the case of the Lighthouse nebula

Lucia Pavan (Université de Genève) - November 28, 2016 at 12:10 pm

The study of outflows from pulsars that are travelling at supersonic velocity through the interstellar medium is recently growing. The outflows produced by hyper-fast pulsars show some peculiar properties, departing significantly from their more common zero/low-velocity cousins. In particular, recent X-ray observations are revealing -against any previous expectation- parsec-scale jets produced by some of the highest velocity pulsars (e.g., the pulsars hosted in the Lighthouse and Guitar nebulae). These jets develop, unbent, almost perpendicularly to their direction of motion. Although several hypotheses have been explored, at present the launching mechanism at the origin of these exceptional jets is still unclear.
I will describe in particular the case of the Lighthouse nebula, a system particularly suited for detailed analyses resolved in space, thanks to its brightness and apparent size. In soft X-rays we clearly disentangle the bow-shock PWN and two large scale jets. The main jet extends helicoidally over ~15 pc and is surrounded by a diffused emission; the counter jet is instead developing in a strikingly straight direction over 1 pc (projected distance). I will review the observational properties of this system and discuss pro and cons of the proposed interpretations for the outflows, in the frame of ballistic jets and in the alternative scenario of diffusion of particles through the surrounding medium.

The seminar will be held in 131A Campbell Hall.

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