222 research outputs found
The Pierre Auger Observatory Open Data
The Pierre Auger Collaboration has embraced the concept of open access to
their research data since its foundation, with the aim of giving access to the
widest possible community. A gradual process of release began as early as 2007
when 1% of the cosmic-ray data was made public, along with 100% of the
space-weather information. In February 2021, a portal was released containing
10% of cosmic-ray data collected from 2004 to 2018, during Phase I of the
Observatory. The Portal included detailed documentation about the detection and
reconstruction procedures, analysis codes that can be easily used and modified
and, additionally, visualization tools. Since then the Portal has been updated
and extended. In 2023, a catalog of the 100 highest-energy cosmic-ray events
examined in depth has been included. A specific section dedicated to
educational use has been developed with the expectation that these data will be
explored by a wide and diverse community including professional and
citizen-scientists, and used for educational and outreach initiatives. This
paper describes the context, the spirit and the technical implementation of the
release of data by the largest cosmic-ray detector ever built, and anticipates
its future developments.Comment: 19 pages, 8 figure
A Search for Photons with Energies Above 2 × 10 eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory
Ultra-high-energy photons with energies exceeding 10 eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 10 eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 × 10 eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 10 and 10 eV
A Search for Photons with Energies above 2 × 1017eV Using Hybrid Data from the Low-Energy Extensions of the Pierre Auger Observatory
Ultra-high-energy photons with energies exceeding 1017 eV offer a wealth of connections to different aspects of cosmic-ray astrophysics as well as to gamma-ray and neutrino astronomy. The recent observations of photons with energies in the 1015 eV range further motivate searches for even higher-energy photons. In this paper, we present a search for photons with energies exceeding 2 × 1017 eV using about 5.5 yr of hybrid data from the low-energy extensions of the Pierre Auger Observatory. The upper limits on the integral photon flux derived here are the most stringent ones to date in the energy region between 1017 and 1018 eV
Radio Measurements of the Depth of Air-Shower Maximum at the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA), part of the Pierre Auger
Observatory, is currently the largest array of radio antenna stations deployed
for the detection of cosmic rays, spanning an area of km with 153
radio stations. It detects the radio emission of extensive air showers produced
by cosmic rays in the MHz band. Here, we report the AERA measurements
of the depth of the shower maximum (), a probe for mass
composition, at cosmic-ray energies between to eV,
which show agreement with earlier measurements with the fluorescence technique
at the Pierre Auger Observatory. We show advancements in the method for radio
reconstruction by comparison to dedicated sets of CORSIKA/CoREAS
air-shower simulations, including steps of reconstruction-bias identification
and correction, which is of particular importance for irregular or sparse radio
arrays. Using the largest set of radio air-shower measurements to date, we show
the radio resolution as a function of energy, reaching a
resolution better than g cm at the highest energies, demonstrating
that radio measurements are competitive with the established
high-precision fluorescence technique. In addition, we developed a procedure
for performing an extensive data-driven study of systematic uncertainties,
including the effects of acceptance bias, reconstruction bias, and the
investigation of possible residual biases. These results have been
cross-checked with air showers measured independently with both the radio and
fluorescence techniques, a setup unique to the Pierre Auger Observatory.Comment: Submitted to Phys. Rev.
Ground observations of a space laser for the assessment of its in-orbit performance
The wind mission Aeolus of the European Space Agency was a groundbreaking
achievement for Earth observation. Between 2018 and 2023, the space-borne lidar
instrument ALADIN onboard the Aeolus satellite measured atmospheric wind
profiles with global coverage which contributed to improving the accuracy of
numerical weather prediction. The precision of the wind observations, however,
declined over the course of the mission due to a progressive loss of the
atmospheric backscatter signal. The analysis of the root cause was supported by
the Pierre Auger Observatory in Argentina whose fluorescence detector
registered the ultraviolet laser pulses emitted from the instrument in space,
thereby offering an estimation of the laser energy at the exit of the
instrument for several days in 2019, 2020 and 2021. The reconstruction of the
laser beam not only allowed for an independent assessment of the Aeolus
performance, but also helped to improve the accuracy in the determination of
the laser beam's ground track on single pulse level. The results presented in
this paper set a precedent for the monitoring of space lasers by ground-based
telescopes and open new possibilities for the calibration of cosmic-ray
observatories.Comment: 10 pages, 10 figure
Constraining models for the origin of ultra-high-energy cosmic rays with a novel combined analysis of arrival directions, spectrum, and composition data measured at the Pierre Auger Observatory
Extraction of the Muon Signals Recorded with the Surface Detector of the Pierre Auger Observatory Using Recurrent Neural Networks
The Pierre Auger Observatory, at present the largest cosmic-ray observatory
ever built, is instrumented with a ground array of 1600 water-Cherenkov
detectors, known as the Surface Detector (SD). The SD samples the secondary
particle content (mostly photons, electrons, positrons and muons) of extensive
air showers initiated by cosmic rays with energies ranging from eV up
to more than eV. Measuring the independent contribution of the muon
component to the total registered signal is crucial to enhance the capability
of the Observatory to estimate the mass of the cosmic rays on an event-by-event
basis. However, with the current design of the SD, it is difficult to
straightforwardly separate the contributions of muons to the SD time traces
from those of photons, electrons and positrons. In this paper, we present a
method aimed at extracting the muon component of the time traces registered
with each individual detector of the SD using Recurrent Neural Networks. We
derive the performances of the method by training the neural network on
simulations, in which the muon and the electromagnetic components of the traces
are known. We conclude this work showing the performance of this method on
experimental data of the Pierre Auger Observatory. We find that our predictions
agree with the parameterizations obtained by the AGASA collaboration to
describe the lateral distributions of the electromagnetic and muonic components
of extensive air showers.Comment: 23 pages, 15 figures. Version accepted for publication in JINS
Deep-learning based reconstruction of the shower maximum Xmax using the water-Cherenkov detectors of the Pierre Auger Observatory
The atmospheric depth of the air shower maximum Xmax is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of Xmax are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of Xmax from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of Xmax. The reconstruction relies on the signals induced by shower particles in the ground based water-Cherenkov detectors of the Pierre Auger Observatory. The network architecture features recurrent long short-term memory layers to process the temporal structure of signals and hexagonal convolutions to exploit the symmetry of the surface detector array. We evaluate the performance of the network using air showers simulated with three different hadronic interaction models. Thereafter, we account for long-term detector effects and calibrate the reconstructed Xmax using fluorescence measurements. Finally, we show that the event-by-event resolution in the reconstruction of the shower maximum improves with increasing shower energy and reaches less than 25 g/cm2 at energies above 2×1019 eV
Demonstrating Agreement between Radio and Fluorescence Measurements of the Depth of Maximum of Extensive Air Showers at the Pierre Auger Observatory
We show, for the first time, radio measurements of the depth of shower
maximum () of air showers induced by cosmic rays that are
compared to measurements of the established fluorescence method at the same
location. Using measurements at the Pierre Auger Observatory we show full
compatibility between our radio and the previously published fluorescence data
set, and between a subset of air showers observed simultaneously with both
radio and fluorescence techniques, a measurement setup unique to the Pierre
Auger Observatory. Furthermore, we show radio resolution as a
function of energy and demonstrate the ability to make competitive
high-resolution measurements with even a sparse radio array.
With this, we show that the radio technique is capable of cosmic-ray mass
composition studies, both at Auger and at other experiments.Comment: Submitted to Phys. Rev. Let
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