144 research outputs found
MUON FLUX ESTIMATION IN THE ANDES UNDERGROUND LABORATORY
The ANDES Underground Laboratory is being planned and designed to be one of the largest and most shielded laboratories in the Southern Hemisphere, which will be located in the Andes Range, in the area of the current Paso AguaNegra that connects the provinces of San Juan (Argentina) and Elqui (Chile). The diversity of experiments that are being planned, including experiments for the direct and indirect search of dark matter and neutrino precision physics, requires a precise knowledge of the flux of high-energy atmospheric muons within the laboratory. These are produced during the interaction of astroparticles with energies between 1012 and 1018eV denominated of high and ultra-high energy withthe Earth’s atmosphere. In the high-energy component, muons with energies of tens of TeV can be found, capable of passing through thousands of meters of rock. Previous estimates made from reasonable assumptions about the type of rock expected in the area showed that the expected muon flux was compatible with other underground laboratories at an equivalent depth. In this work, extensive atmospheric showers flux simulations were performed at the laboratory site.Afterwards, there was a selection of those muons with sufficient energy to reach the laboratory based on their angle of incidence and the height at which they enter the mountain. Then a transfer function was modeled using the new geological studies currently available that allow us to have a detailed model of the rock distribution inside the mountain. Finally, the interaction of these muons with the different types of rock was calculated numerically along their way to the laboratory using the continuous slow-down approximation, thus obtaining that the expected muon flux within the laboratory is 1,47±0,02 day−1m−2sr−1
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
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.
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
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
Design and implementation of the AMIGA embedded system for data acquisition
The Auger Muon Infill Ground Array (AMIGA) is part of the AugerPrime upgrade
of the Pierre Auger Observatory. It consists of particle counters buried 2.3 m
underground next to the water-Cherenkov stations that form the 23.5 km
large infilled array. The reduced distance between detectors in this denser
area allows the lowering of the energy threshold for primary cosmic ray
reconstruction down to about 10 eV. At the depth of 2.3 m the
electromagnetic component of cosmic ray showers is almost entirely absorbed so
that the buried scintillators provide an independent and direct measurement of
the air showers muon content. This work describes the design and implementation
of the AMIGA embedded system, which provides centralized control, data
acquisition and environment monitoring to its detectors. The presented system
was firstly tested in the engineering array phase ended in 2017, and lately
selected as the final design to be installed in all new detectors of the
production phase. The system was proven to be robust and reliable and has
worked in a stable manner since its first deployment.Comment: Accepted for publication at JINST. Published version, 34 pages, 15
figures, 4 table
AugerPrime Surface Detector Electronics
Operating since 2004, the Pierre Auger Observatory has led to major advances
in our understanding of the ultra-high-energy cosmic rays. The latest findings
have revealed new insights that led to the upgrade of the Observatory, with the
primary goal of obtaining information on the primary mass of the most energetic
cosmic rays on a shower-by-shower basis. In the framework of the upgrade,
called AugerPrime, the 1660 water-Cherenkov detectors of the surface array are
equipped with plastic scintillators and radio antennas, allowing us to enhance
the composition sensitivity. To accommodate new detectors and to increase
experimental capabilities, the electronics is also upgraded. This includes
better timing with up-to-date GPS receivers, higher sampling frequency,
increased dynamic range, and more powerful local processing of the data. In
this paper, the design characteristics of the new electronics and the enhanced
dynamic range will be described. The manufacturing and test processes will be
outlined and the test results will be discussed. The calibration of the SD
detector and various performance parameters obtained from the analysis of the
first commissioning data will also be presented
Cosmological implications of photon-flux upper limits at ultra-high energies in scenarios of Planckian-interacting massive particles for dark matter
We present a thorough search for signatures that would be suggestive of
super-heavy particles decaying in the Galactic halo, in the data of the
Pierre Auger Observatory. From the lack of signal, we derive upper limits for
different energy thresholds above \,GeV on the expected
secondary by-product fluxes from -particle decay. Assuming that the energy
density of these super-heavy particles matches that of dark matter observed
today, we translate the upper bounds on the particle fluxes into tight
constraints on the couplings governing the decay process as a function of the
particle mass. We show that instanton-induced decay processes allow us to
derive a bound on the reduced coupling constant of gauge interactions in the
dark sector: \alpha_X \alt 0.09, for 10^{9} \alt M_X/\text{GeV} < 10^{19}.
This upper limit on is complementary to the non-observation of
tensor modes in the cosmic microwave background in the context of
Planckian-interacting massive particles for dark matter produced during the
reheating epoch. Viable regions for this scenario to explain dark matter are
delineated in several planes of the multidimensional parameter space that
involves, in addition to and , the Hubble rate at the end of
inflation, the reheating efficiency, and the non-minimal coupling of the Higgs
with curvature.Comment: 15 pages, 8 figures, Accompanying paper of arXiv:2203.0885
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
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