28295913
Search for compact sources of cosmic photons above 200 TeV.
From April 1988 to February 1990 we used a two-level array of scintillators to search in the cosmic radiation for compact sources of {gamma} rays above 200 TeV. Counters on the surface measured the size and direction of extensive air showers while counters buried 3 m below ground measured their muon content. Showers induced by {gamma} rays are expected to have many fewer muons than those initiated by hadrons so the selection of muon-poor showers should greatly reduce the background of hadronic showers. Three objects, Cygnus X-3, the Crab nebula, and Hercules X-1, were examined in detail. Searches were made on short and long time scales and source periodicity was used, where applicable, to enhance any possible signals. We found no evidence for any compact sources.
55258398
Absolute photometric calibration of large aperture optical systems
Abstract A method of absolute calibration for the air shower fluorescence detectors of the Pierre Auger Observatory is presented, along with preliminary results from prototype equipment. A 2.5 m diameter light source uniformly illuminated by ultra-violet light emitting diodes is calibrated and mounted at the detector aperture. The resulting end-to-end measurement provides a 7% absolute photon calibration at a wavelength of 375 nm.
118712145
High energy astrophysics : models and observations from MeV to EeV
Gamma ray line radiation, R. Ramaty and R. Lingenfelter gamma ray bursters, D. Hartmann gamma ray astronomy above 0.1TeV, D.J.Fegan cosmic ray observations at extreme energies, P. Sokolsky astrophysical neutrinos, T. Stanev AGN and galactic sites of cosmic ray origin, P.L. Biermann.
116163246
Recent results on nucleon decay from IMB
116660720
Measuring the Highest Energy Cosmic Rays: The Auger project
118964615
Atmospheric aerosol monitoring at the Pierre Auger Observatory
For a ground based cosmic-ray observatory the atmosphere is an integral part of the detector. Air fluorescence detectors (FDs) are particularly sensitive to the presence of aerosols in the atmosphere. These aerosols, consisting mainly of clouds and dust, can strongly affect the propagation of fluorescence and Cherenkov light from cosmic-ray induced extensive air showers. The Pierre Auger Observatory has a comprehensive program to monitor the aerosols within the atmospheric volume of the detector. In this paper the aerosol parameters that affect FD reconstruction will be discussed. The aerosol monitoring systems that have been deployed at the Pierre Auger Observatory will be briefly described along with some measurements from these systems.
23690451
Systematics of inclusive pion double charge exchange in the delta resonance region.
A systematic study of inclusive pion double charge exchange is reported for nuclei between A=16 and A=208. The doubly differential cross sections for the A(${\mathrm{\ensuremath{\pi}}}^{+}$,${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$) and A(${\mathrm{\ensuremath{\pi}}}^{\mathrm{\ensuremath{-}}}$,${\mathrm{\ensuremath{\pi}}}^{+}$) reactions in $^{16}\mathrm{O}$, $^{40}\mathrm{Ca}$, $^{103}\mathrm{Rh}$, and $^{208}\mathrm{Pb}$ were measured at incident energies between 120 and 270 MeV at three to five outgoing pion angles. Pion spectra were measured over the energy range from 10 MeV to the kinematic limit for double charge exchange. Integrating these spectra over outgoing pion energy generated angular distributions, and subsequently integrating these angular distributions generated total reaction cross sections. The shapes of the measured spectra are compared with those determined by the distribution of events in four-body phase space and with those predicted by a model in which the pion undergoes two sequential single charge exchanges on nucleons in a Fermi gas. The cross sections are compared with predictions of cascade calculations in which more than two interactions, including pion absorption and scattering without charge exchange, may occur.