Speaker
Description
Radio detection of cosmic rays has not only been shown to be complementary to classical detection methods but also advantageous as the full shower profile can be extracted, which in turn can provide more physical knowledge about the air shower than already known today. However, the full reconstruction of the profile requires an efficient 4-D imaging algorithm due to the strong spatial and temporal dependence on the shower evolution and emission. Classical radio interferometric algorithms cannot fully extract the shower profile due to the non-repeating and near-field nature of the radio pulses, even when utilising dense detector layouts such as the LOw Frequency ARray (LOFAR) or the upcoming Square Kilometre Array (SKA). However, with the recent development of Information Field Theory (IFT), a Bayesian framework applied on field-like structures, we can not only perform 4-D interferometric imaging in a timely manner but also incorporate the well-known physical characteristics of the emission for reconstruction.
In this work, we develop an IFT-based imaging algorithm for extensive air showers that utilises prior physical information of the emission process to reconstruct the longitudinal profile of the air shower. We utilise the template synthesis approach (Desmet et al. 2024, Astroparticle Physics 157, 102923) to construct a fast-forward model that generates electric field traces at each radio antenna from a shower profile following the Gaisser-Hillas function. The longitudinal profile is reconstructed by using IFT to infer the model parameters that describe the shower profile. We apply our approach to reconstruct the profile from realistic simulated events generated from CoREAS simulations based on the CORSIKA simulation framework with the LOFAR detector layout. We analyse the reconstruction efficiency of our model to standard profile parameters such as $X_\mathrm{max}$ to highlight the performance of our model. We plan to optimise our algorithm to efficiently reconstruct the profile on the planned SKA detector layout.
