Search arXiv⌕ Search

arXiv subjects

D. Nitz

Publications and source records attributed to D. Nitz.

6 recordsLinked to original sources
arXiv2021

Calibration of the Surface Array of the Pierre Auger Observatory

The Pierre Auger Observatory is designed to study cosmic rays of the highest energies ($>10^{19}$ eV). The ground array of the Observatory will consist of 1600 water Cherenkov detectors deployed over 3000 km^2. The remoteness and large number of detectors require a robust, automatic self-calibration procedure. It relies on the measurement of the average charge collected by a photomultiplier tube from the Cherenkov light produced by a vertical and central through-going muon determined to 5 - 10% at the detector via a novel rate-based technique and to 3% precision through analysis of histograms of the charge distribution. The parameters needed for the calibration are measured every minute, allowing for an accurate determination of the signals recorded from extensive air showers produced by primary cosmic rays. The method also enables stable and uniform triggering conditions to be achieved.

astro-ph.HE↗
arXiv2007

The Northern Site of the Pierre Auger Observatory

The Pierre Auger Observatory is a multi-national project for research on ultra-high energy cosmic rays. The Southern Auger Observatory in Mendoza province, Argentina, is approaching completion in 2007 with an instrumented area of 3,000 km^2. It will accurately measure the spectrum and composition of ultra-high energy cosmic rays up to and beyond the predicted GZK feature. We are obtaining results on the energy spectrum, mass composition and distribution of arrival directions on the southern sky. The Northern Auger Observatory is designed to complete and extend the investigations begun in the South. It will establish charged particle astronomy and thus open a new window into the universe. The distribution of arrival directions of the highest energy events will point the way to unveiling the almost century old mystery of the origin and nature of ultra-high energy cosmic rays. Achieving this goal requires collecting many more events in spite of the steeply falling energy spectrum. The planned northern site will have an instrumented area of 4,000 square miles (10,370 km}^2 in Southeast Colorado, USA. The paper covers the science of charged particle astronomy, the layout and the technical implementation of the Northern Auger Observatory.

astro-ph↗
arXiv2005

The trigger system of the Pierre Auger Surface Detector: operation, efficiency and stability

The trigger system of the Surface Detector (SD) of the Pierre Auger Observatory is described, from the identification of candidate showers ($E>1$ EeV) at the level of a single station, among a huge background (mainly single muons), up to the selection of real events and the rejection of random coincidences at a higher central trigger level (including the reconstruction accuracy). Efficiency of a single station trigger is evaluated using real data , and the high performance of event selection hierarchy will be demonstrated.

astro-ph↗
arXiv2005

Detecting gamma-ray bursts with the Pierre Auger Observatory using the single particle technique

During the past ten years, gamma-ray bursts (GRB) have been extensively studied in the keV-MeV energy range but the high energy emission still remain mysterious. Ground based observatories have the possibility to investigate energy range around one GeV using the "single particle technique". The aim of the present study is to investigate the capability of the Pierre Auger Observatory to detect the high energy emission of GRBs with such a technique. According to the detector response to photon showers around one GeV, and making reasonable assumptions about the high energy emission of GRBs, we show that the Pierre Auger Observatory is a competitive instrument for this technique, and that water tanks are very promising detectors for the single particle technique.

astro-ph↗
arXiv1997

Constraints on Gamma-ray Emission from the Galactic Plane at 300 TeV

We describe a new search for diffuse ultrahigh energy gamma-ray emission associated with molecular clouds in the galactic disk. The Chicago Air Shower Array (CASA), operating in coincidence with the Michigan muon array (MIA), has recorded over 2.2 x 10^{9} air showers from April 4, 1990 to October 7, 1995. We search for gamma rays based upon the muon content of air showers arriving from the direction of the galactic plane. We find no significant evidence for diffuse gamma-ray emission, and we set an upper limit on the ratio of gamma rays to normal hadronic cosmic rays at less than 2.4 x 10^{-5} at 310 TeV (90% confidence limit) from the galactic plane region: (50 degrees < l < 200 degrees); -5 degrees < b < 5 degrees). This limit places a strong constraint on models for emission from molecular clouds in the galaxy. We rule out significant spectral hardening in the outer galaxy, and conclude that emission from the plane at these energies is likely to be dominated by the decay of neutral pions resulting from cosmic rays interactions with passive target gas molecules.

astro-ph↗