What are the New Observations About Gamma Ray Wavefronts?

Wavefronts of Four Different 100 GeV Showers at VERITAS

We noticed that not all gamma ray showers are created equally (as waspreviously thought). There is a wide variety of appearences to the wavefrontsof gamma ray showers. In investigating these differences, it was eventuallydiscovered that the shape of the wavefront is determined by the altitude atwhich the photons are emitted in a shower. The overall shape of the wavefrontis hyperbolic. Photons emitted above 10,000 m produce a relatively flat curve. As the altitude is lowerd the hyperbola becomes narrower and narrower untilfinally , at very low emission altitudes (below 6000 m) the hyperbola becomesalmost conical. When this information is combined with the observation thatgamma rays can initially interact at random altitudes it can be seen that greatirregularities exist in wavefront shapes.

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