Features of arrival time and angle-of-incidence distributions of EAS muons

Charakteristika und Abhängigkeiten von Ankunftszeit- und Einfallswinkelverteilungen von Myonen ausgedehnter Luftschauer Verschiedene charakteristische Eigenschaften und Korrelationen von Ankunftszeit- und Einfallswinkelverteilungen von Myonen ausgedehnter Luftschauer (EAS) werden untersucht auf der Grundlage von Monte-Carlo Simulationen der EAS Entwicklung mit Hilfe des Simulations-Codes CORSIKA. Die Ankunftszeitverteilungen und Winkel-verteilungen werden charakterisiert durch die Ankunftszeit bzw. Einfallswinkel des ersten Myons, durch Mittelwerte und Median-Werte der Verteilungen in den einzelnen Schauern. Spezielles Augenmerk wird gerichtet auf Vielfach-Korrelationen bei gleichzeitigen Beobachtungen in verschiedenen Abständen vom Schauer-Zentrum. Es wird gezeigt, daß ein solcher Beobachtungsmode zusätzliche Informationen zur Verbesserung der Unterscheidung der Art der Primärteilchen liefert

Observation of a sudden cessation of a very-high-energy gamma-ray flare in PKS 1510-089 with H.E.S.S. and MAGIC in May 2016

The flat spectrum radio quasar (FSRQ) PKS 1510-089 is known for its complex multiwavelength behavior, and is one of only a few FSRQs detected at very high energy (VHE, E >100 GeV) -rays. VHE -ray observations with H.E.S.S. and MAGIC during late May and early June 2016 resulted in the detection of an unprecedented flare, which reveals for the first time VHE -ray intranight variability in this source. While a common variability timescale of 1.5 hr is found, there is a significant deviation near the end of the flare with a timescale of ∼ 20 min marking the cessation of the event. The peak flux is nearly two orders of magnitude above the low-level emission. For the first time, curvature is detected in the VHE -ray spectrum of PKS 1510-089, which is fully explained through absorption by the extragalactic background light. Optical R-band observations with ATOM reveal a counterpart of the -ray flare, even though the detailed flux evolution differs from the VHE lightcurve. Interestingly, a steep flux decrease is observed at the same time as the cessation of the VHE flare. In the high energy (HE, E >100 MeV) -ray band only a moderate flux increase is observed with Fermi-LAT, while the HE -ray spectrum significantly hardens up to a photon index of 1.6. A search for broad-line region (BLR) absorption features in the -ray spectrum indicates that the emission region is located outside of the BLR. Radio VLBI observations reveal a fast moving knot interacting with a standing jet feature around the time of the flare. As the standing feature is located ∼ 50 pc from the black hole, the emission region of the flare may have been located at a significant distance from the black hole. If this correlation is indeed true, VHE rays have been produced far down the jet where turbulent plasma crosses a standing shock.Accepted manuscrip

Arrival time distributions of muons from extensive air showers as signature of the mass composition of cosmic rays

The central detector of the KASCADE experiment which intends to study the main components of extensive air showers will be equipped with a trigger and fast timing facility which enables measurements of the arrival time distributions of the muons. In particular, at larger distances from the shower axis the arrival time distributions are expected to map the longitudinal development of the showers in the atmosphere and may provide additional information about the nature of the primary particle through differences of the mean-free paths and the interaction cross sections with air nuclei. We have investigated this aspect with respect to the KASCADE setup on the basis of EAS-simulations using the Monte-Carlo code CORSIKA. The mean arrival time distributions of muons, observed at various distances from the shower core and for different primary energies and showers sizes, respectively, have been analysed with advanced statistical techniques, based on Bayes decision rules and nonparametric multivariate analysing methods, in order to specify the merits of the mean arrival time information of the muon component as a signature for the mass composition of cosmic rays. It turns out that muon arrival time distributions, observed with the KASCADE facility, exhibit promising features and mass discrimination effects for larger shower sizes, i.e. higher primary energies, around 10"1"6 eV. (orig.)Available from TIB Hannover: ZA 5141(5398) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Proceedings of the workshop ANI 98 Current topics of cosmoic ray research with EAS observations

The following topics were dealt with: EAS signatures, cosmic ray mass composition in the PeV region, KASCADE experiment, cosmic ray energy composition, cosmic ray elemental composition, EAS analysis by nonparametric methods, soft EAS component, hadronic EAS component, GAMMA array measurements, EAS muon characteristics, muon detector response studies with the simulation program ARES, GAMMA array measurement accuracy, EAS charged particle component, EAS size spectrum, MAKET installation, EAS size spectra in the knee region, cosmic ray background flux at Aragat, EAS selection, muon arrival time, muon angle of incidence distributions, EAS simulations, GAMMA muon underground detectors, superhigh energy hadron production, high energy hadron interaction models, KORSICA code verification, charge ratio of cosmic ray muonsAvailable from TIB Hannover: ZA 5141(6215) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Features of arrival time and angle-of-incidence distributions of EAS muons

Various features and correlations of the arrival time and angle-of-incidence distributions of muons of extensive air showers (EAS) are studied by analyses based on Monte-Carlo simulations of the EAS development by use the air shower simulation code CORSIKA. Trends and dependencies of the temporal dispersion of the EAS muon component on shower size and distance from the shower core are displayed by the distribution of the arrival time and angle of incidence of the first muon, of the mean and median of the single shower distribution. Special attention is called to multi-correlations in observations at different radial distances from the shower core, which are shown to provide additional information in view of a discrimination of different EAS primaries. (orig.)25 refs.Available from TIB Hannover: ZA 5141(5835) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman