41 research outputs found
vs. from Extensive Air Showers as estimator for the mass of primary UHECR's. Application for the Pierre Auger Observatory
We study the possibility of primary mass estimation for Ultra High Energy
Cosmic Rays (UHECR's) using the (the height where the number of
muons produced on the core of Extensive Air Showers (EAS) is maximum) and the
number of muons detected on ground. We use the 2D distribution -
against in order to find its sensitivity to the mass
of the primary particle. For that, we construct a 2D Probability Function
which estimates the probability that a
certain point from the plane , corresponds to a
shower induced by a proton, respectively an iron nucleus. To test the
procedure, we analyze a set of simulated EAS induced by protons and iron nuclei
at energies of and zenith angle with CORSIKA. Using
the Bayesian approach and taking into account the geometry of the infill
detectors from the Pierre Auger Observatory, we observe an improvement in the
accuracy of the primary mass reconstruction in comparison with the results
obtained using only the distributions
Cosmic ray mass composition at the knee using azimuthal fluctuations of air shower particles detected at ground by the KASCADE experiment
The presence of hadronic sub-showers causes azimuthal non-uniformity in the
particle distributions on the ground in vertical air showers. The
parameter, which quantifies the non-uniformity of the signal recorded in
detectors located at a given distance on a ring around the shower axis, has
been successfully introduced as a gamma/hadron discriminator at PeV energies
\cite{Conceicao:2022lkc}. In this work, we demonstrate that the parameter
can effectively serve as a mass composition discriminator in experiments that
employ a compact array of detectors, like KASCADE. We reconstruct the
parameter distributions in the energy range using measurements from the KASCADE experiment, with intervals of
, which are then fitted with MC templates for five primary
nuclei species p, He, C, Si, and Fe considering three hadronic interaction
models: QGSjet-II-04, EPOS-LHC and SIBYLL 2.3d. We find that the
parameter exhibits minimal dependence on the specific hadronic interaction
model considered. The reconstructed fractions of individual species demonstrate
a linear decrease in the abundance of protons and He nuclei with increasing
energy, while the heavier components become prevalent above the \textit{knee}
as predicted by all three hadronic interaction models. Our findings indicate
that the abundance of particle types as a function of energy aligns with
different astrophysical models that link the \textit{knee} to the acceleration
and propagation of cosmic rays within the Galaxy. Furthermore, they also
demonstrate excellent agreement with three more recent data-driven
astrophysical models. These findings suggest that the parameter could be
a valuable tool for forthcoming measurements of the LHAASO experiment to
enhance our knowledge about the origin and acceleration mechanisms of cosmic
rays.Comment: Accepted for publication in this form in JCA
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file