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Register a new userAnalysis of Scattering from Archival Pulsar Data using a CLEAN-based Method
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In this work we adopted a CLEAN-based method to determine the scatter time, $tau$, from archived pulsar profiles under both the thin screen and uniform medium scattering models and to calculate the scatter time frequency scale index $alpha$ where $taupropto u^{alpha}$. The value of $alpha$ is $-4.4$, if a Kolmogorov spectrum of the interstellar medium turbulence is assumed. We deconvolved 1342 profiles from 347 pulsars over a broad range of frequencies and dispersion measures. In our survey, in the majority of cases the scattering effect was not significant compared to pulse profile widths. For a subset of 21 pulsars scattering at the lowest frequencies was large enough to be measured. Because reliable scatter time measurements were determined only for the lowest frequency, we were limited to using upper limits on scatter times at higher frequencies for the purpose of our scatter time frequency slope estimation. We scaled the deconvolved scatter time to 1~GHz assuming $alpha=-4.4$ and considered our results in the context of other observations which yielded a broad relation between scatter time and dispersion measure.
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Cosmic ray data collected by the KASCADE air shower experiment are competitive in terms of quality and statistics with those of modern observatories. We present a novel mass composition analysis based on archival data acquired from 1998 to 2013 provided by the KASCADE Cosmic ray Data Center (KCDC). The analysis is based on modern machine learning techniques trained on simulation data provided by KCDC. We present spectra for individual groups of primary nuclei, the results of a search for anisotropies in the event arrival directions taking mass composition into account, and search for gamma-ray candidates in the PeV energy domain.
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