相关论文: A Likelihood Method for Measuring the Ultrahigh En…
We describe a new approach to establishing the mass composition at high energies. Based on measuring both the vertical and inclined shower rates, it has the potential to distinguish heavy nuclei from light nuclei. We apply the method to…
In a standard method of determining electron density for soft X-ray (SXR) flare kernels it is necessary to assume what is the extension of a kernel along the line of sight. This is a source of significant uncertainty of the obtained…
A fluorescent image analysis procedure to determine the distribution of species concentration and density in a gas flow is proposed. The fluorescent emission is due to the excitation of atoms/molecules of a gas that is intercepted by an…
Spatial distributions of electrons ionized and scattered from ultra-low pressure gases are proposed and experimentally demonstrated as a method to directly measure the intensity of an ultra-high intensity laser pulse. Analytic models…
Cosmic rays with energies exceeding $10^{17}$ eV are frequently registered by measurements of the fluorescence light emitted by extensive air showers. The main uncertainty for the absolute energy scale of the measured air showers is coming…
The KASCADE experiment measures a high number of EAS observables with a large degree of sampling of the electron-photon, muon, and hadron components. It provides accurate data for an event-by-event analysis of the primary cosmic ray flux in…
The observation of the Moon shadow effect with the L3+C detector is reported. The expected offset and elongation of the Moon shadow due to the geomagnetic field are clearly observed. A determination of the angular resolution and pointing…
Over the last years, radio detection has matured to become a competitive method for the detection of air showers. Arrays of thousands of antennas are now envisioned for the detection of cosmic rays of ultra high energy or neutrinos of…
We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 10^17.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for…
Understanding the sources, acceleration mechanisms, and propagation of cosmic rays is an active area of research in astro-particle physics. Measuring the spectrum and elemental composition of cosmic rays on earth can help solve this…
We show, for the first time, radio measurements of the depth of shower maximum ($X_\text{max}$) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using…
The mass composition of ultra-high-energy cosmic rays (UHECRs) is usually inferred from the depth of the shower maximum ($X_{\rm{max}}$) of cosmic-ray showers, which is only ambiguously determined by modern hadronic interaction models. We…
An approach for measuring energy of cosmic-ray particles with energies E > 10^12 eV using an ultrathin calorimeter is presented. The method is based on the analysis of the correlation dependence of the cascade size on the rate of…
Detection of (ultra-) high-energy cosmic rays with the use of radio frequency emission from extensive air showers has been proven as complimentary to existing ground array detection techniques. Great progress has been made in the…
In this paper, we will discuss the prospects of deducing the proton-air cross section from fluorescence telescope measurements of extensive air showers. As it is not possible to observe the point of first interaction $X_{\rm 1}$ directly,…
This paper summarizes the status and the recent measurements from the Pierre Auger Observatory. The energy spectrum is described and its features discussed. We report searches for anisotropy of cosmic ray arrival directions on large scales…
The mass composition of ultra high-energy cosmic ray (UHECRs) can be inferred from measurements of $X_{\rm max}$ distributions by fitting them with Monte Carlo (MC) predictions for different primary species of nuclei in each energy…
We compare the propagation of iron and proton nuclei above 10^19 eV in a structured Universe with source and magnetic field distributions obtained from a large scale structure simulation and source densities about 10^(-5) Mpc^(-3). All…
The HEGRA system of 4 Imaging Atmospheric Cherenkov Telescopes (IACTs) has been used to determine the flux and the spectrum of cosmic ray protons over a limited energy range around 1.5 TeV. Although the IACT system is designed for the…
We compare the expected contribution of FR-II hot spots to the ultra-high energy cosmic ray spectrum (Rachen & Biermann 1993, A&A in press, BB paper astro-ph/9301010) to improved experimental results. We introduce a "world data set" of UHE…