212 research outputs found
The Pierre Auger Project and Enhancements
The current status of the scientific results of the Auger Observatory will be
discussed which include spectrum, anisotropy in arrival directions, chemical
composition analyses, and limits on neutrino and photon fluxes. A review of the
Observatory detection systems will be presented. Auger has started the
construction of its second phase which encompasses antennae for radio detection
of cosmic rays, high-elevation telescopes, and surface plus muon detectors.
Details will be presented on the latter, AMIGA (Auger Muons and Infill for the
Ground Array), an Auger project consisting of 85 detector pairs each one
composed of a surface water-Cherenkov detector and a buried muon counter. The
detector pairs are arranged in an array with spacings of 433 and 750 m in order
to perform a detailed study of the 10^17 eV to 10^19 eV spectrum region.
Preliminary results on the performance of the 750 m array of surface detectors
and the first muon counter prototype will be presented.Comment: 10 pages, 8 figures, VIII Latin American Symposium on Nuclear Physics
and Applications December 15-19, 2009, Santiago, Chil
Deployment and performance of a Low-Energy-Threshold Skipper-CCD inside a nuclear reactor
Charge Coupled Devices (CCD) are used for reactor neutrino experiments and
already shown their potential in constraining new physics models. The prospect
of a Skipper-CCD experiment looking for standard and beyond standard model
physics (BSM) in a nuclear reactor has been recently evaluated for different
benchmark scenarios. Here we report the installation of the first 2 g
Skipper-CCD inside the containment building of a 2 GW nuclear power
plant, positioned 12 meters from the center of the reactor core. We discuss the
challenges involved in the commissioning of the detector and present data
acquired during reactor ON and reactor OFF periods, with the detector operating
with a sub-electron readout noise of 0.17 e-. The ongoing efforts to improve
sensitivities to CEvNS and BSM interaction are also discussed.Comment: 12 pages, 7 figures, 1 tabl
A search for point sources of EeV photons
Measurements of air showers made using the hybrid technique developed with
the fluorescence and surface detectors of the Pierre Auger Observatory allow a
sensitive search for point sources of EeV photons anywhere in the exposed sky.
A multivariate analysis reduces the background of hadronic cosmic rays. The
search is sensitive to a declination band from -85{\deg} to +20{\deg}, in an
energy range from 10^17.3 eV to 10^18.5 eV. No photon point source has been
detected. An upper limit on the photon flux has been derived for every
direction. The mean value of the energy flux limit that results from this,
assuming a photon spectral index of -2, is 0.06 eV cm^-2 s^-1, and no celestial
direction exceeds 0.25 eV cm^-2 s^-1. These upper limits constrain scenarios in
which EeV cosmic ray protons are emitted by non-transient sources in the
Galaxy.Comment: 28 pages, 10 figures, accepted for publication in The Astrophysical
Journa
Reconstruction of inclined air showers detected with the Pierre Auger Observatory
We describe the method devised to reconstruct inclined cosmic-ray air showers
with zenith angles greater than detected with the surface array of
the Pierre Auger Observatory. The measured signals at the ground level are
fitted to muon density distributions predicted with atmospheric cascade models
to obtain the relative shower size as an overall normalization parameter. The
method is evaluated using simulated showers to test its performance. The energy
of the cosmic rays is calibrated using a sub-sample of events reconstructed
with both the fluorescence and surface array techniques. The reconstruction
method described here provides the basis of complementary analyses including an
independent measurement of the energy spectrum of ultra-high energy cosmic rays
using very inclined events collected by the Pierre Auger Observatory.Comment: 27 pages, 19 figures, accepted for publication in Journal of
Cosmology and Astroparticle Physics (JCAP
Highlights from the Pierre Auger Observatory
The Pierre Auger Observatory is the world's largest cosmic ray observatory.
Our current exposure reaches nearly 40,000 km str and provides us with an
unprecedented quality data set. The performance and stability of the detectors
and their enhancements are described. Data analyses have led to a number of
major breakthroughs. Among these we discuss the energy spectrum and the
searches for large-scale anisotropies. We present analyses of our X
data and show how it can be interpreted in terms of mass composition. We also
describe some new analyses that extract mass sensitive parameters from the 100%
duty cycle SD data. A coherent interpretation of all these recent results opens
new directions. The consequences regarding the cosmic ray composition and the
properties of UHECR sources are briefly discussed.Comment: 9 pages, 12 figures, talk given at the 33rd International Cosmic Ray
Conference, Rio de Janeiro 201
Operations of and Future Plans for the Pierre Auger Observatory
Technical reports on operations and features of the Pierre Auger Observatory,
including ongoing and planned enhancements and the status of the future
northern hemisphere portion of the Observatory. Contributions to the 31st
International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
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