7-11 July 2014
Africa/Johannesburg timezone
<a href="http://events.saip.org.za/internalPage.py?pageId=16&confId=34"><font color=#0000ff>SAIP2014 Proceedings published on 17 April 2015</font></a>

Spectral modelling of H.E.S.S.-detected PWNe

9 Jul 2014, 11:10
20m
D Les 203

D Les 203

Oral Presentation Track D1 - Astrophysics Astro

Speaker

Carlo van Rensburg (North West University)

Abstract content <br> &nbsp; (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>

In the last decade ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs) have discovered almost 150 very-high-energy (VHE; E > 100 GeV) γ-ray sources. Roughly 30 of these are confirmed pulsar wind nebulae (PWNe), while other source classes include supernova remnants, active galactic nuclei, or unidentified sources. A subset of latter may eventually turn out to be PWNe. It has been noted that the TeV flux of PWNe does not correlate with the spin-down luminosity of their embedded pulsars and it is currently unclear whether there is any correlation between the TeV surface brightness of the PWNe and the spin-down luminosity of the associated pulsar. We will present first results from an emission code that models the spectral energy density (SED) of a PWN by solving the Fokker-Planck transport equation. Although models such as these have been developed before, most of them model the geometry of a PWN as that of a single sphere. We have created a time-dependent, multi-zone model to investigate changes in the particle spectrum as the particles diffuse through the PWN, as well as the predicted radiation spectrum at different positions in the PWN. We will use the model to fit observed spectra of several PWNe that are not point sources, incorporating data from the High Energy Stereoscopic System (H.E.S.S.) as well as radio and X-ray experiments. Once the model has been calibrated, we will perform a population study to probe a potential relationship between the TeV surface brightness and the spin-down luminosity of the embedded pulsar.

Level for award<br>&nbsp;(Hons, MSc, <br> &nbsp; PhD)?

MSc

Apply to be<br> considered for a student <br> &nbsp; award (Yes / No)?

Yes

Main supervisor (name and email)<br>and his / her institution

Paulus Kruger Paulus.Kruger@nwu.ac.za

Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?

Yes

Primary author

Carlo van Rensburg (North West University)

Co-authors

Dr Christo Venter (North-west University) Dr Paulus Kruger (NWU)

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