Presentation materials
The excess of gamma rays in the data measured by the Fermi Large Area Telescope from the Galactic center region is one of the most intriguing mysteries in Astroparticle Physics. This Galactic center excess (GCE), has been measured with respect to different interstellar emission models, source catalogs, data selections and techniques. Although several proposed interpretations have appeared in...
The present work is dedicated to dark matter indiret searches and derived the robust constraints on annihilating WIMP parameters utilizing new radio observations of M31, as well as new studies of its dark matter distribution and other properties. The characteristics of emission due to DM annihilation were computed in the frame of 2D galactic model employing GALPROP code adapted specifically...
We present a thorough search for signatures that would be suggestive of super-heavy
We present a new reconstruction of the distribution of atomic hydrogen in the inner Galaxy that is based on explicit radiation-transport modelling of line and continuum emission and a gas-flow model in the barred Galaxy that provides distance resolution for lines of sight toward the Galactic Center. The main benefits of the new gas model are, a), the ability to reproduce the negative line...
Among many earth-bound experimental attempts to detect dark matter (DM) particles, the DAMA/LIBRA experiment is the only one that has been claiming to observe the annual modulation of the event rate in the detector expected from DM in the Milky Way. The experiment is detecting the modulation signal for more than two decades with a statistical significance of 13.7 sigma. However, numerous null...
Thanks to tremendous experimental efforts, galactic cosmic-ray fluxes are being measured up to the unprecedented percent precision level. The logarithmic slope of these fluxes is a crucial quantity that promises us information on the diffusion properties and the primary or secondary nature of the different species. However, these measured slopes are sometimes interpreted in the pure diffusive...
Analysis of anisotropy of the arrival directions of galactic positrons and electrons has been performed with the Alpha Magnetic Spectrometer on the International Space Station. These results differentiate between point-like and diffuse sources of cosmic rays for the explanation of the observed excess of high energy positrons. The AMS results of the dipole anisotropy are presented along with...
Precision measurements of cosmic ray positrons are presented up to 1.4 TeV based on 3.4 million positrons collected by the Alpha Magnetic Spectrometer on the International Space Station. The positron flux exhibits complex energy dependence. Its distinctive properties are: (a) a significant excess starting from 24.2 GeV compared to the lower-energy, power-law trend; (b) a sharp drop-off above...
The DArk Matter Particle Explorer (DAMPE) is a space-based particle detector launched on December 2015 from the Jiuquan Satellite Launch Center, in China and since then smoothly operating in a Sun-synchronous orbit. The main goals of the DAMPE mission include the study of the Cosmic-Ray Electron-positron (CRE) energy spectrum, the study of galactic cosmic-rays (CR), gamma-ray astronomy, and...
Deuterons and ยณHe represent a few per cent of the cosmic-ray nuclei. They are mainly produced by fragmentation reactions of primary cosmic โดHe nuclei on the interstellar medium and represent a very sensitive tool to verify and constrain CR propagation models in the galaxy, providing additional information to that of the cosmic B/C ratio. Precision measurements of the deuteron and ยณHe fluxes...
Beryllium nuclei are expected to be mainly produced by the fragmentation of primary cosmic rays (CR) during their propagation. Therefore, their measurement is essential in the understanding of cosmic ray propagation and sources. In particular, the ยนโฐBe/โนBe ratio can be used as a radioactive clock providing the measurement of CR residence time in the Galaxy. In this contribution, the...
The Alpha Magnetic Spectrometer collected over 150 billion cosmic rays events during the first 8.5 years of operation aboard the International Space Station. A component of Z>2 ions with rigidities below the rigidity cutoff and located in the South Atlantic Anomaly have been measured both in the down-going and up-going direction.
We present an updated analysis of the mass composition of cosmic rays in the
We review the improvements to the reconstruction setup based on Corsika/CoREAS simulations, as well as the selection method to obtain a minimally biased $X_{\rm...
The energy spectrum and mass composition of ultra-high energy cosmic rays inferred at the Pierre Auger Observatory are used to derive a benchmark scenario for the emission mechanisms at play in extragalactic accelerators as well as for their energetics and for the abundances of elements in their environments. Assuming a distribution of sources following the density of stellar mass, the gradual...
Mini-EUSO is a telescope launched on board the International Space Station in 2019 and currently located in the Russian section of the station and viewing our planet from a nadir-facing UV-transparent window in the Zvezda module. The instrument is based on an optical system employing two Fresnel lenses and a focal surface composed of 36 Multi-Anode Photomultiplier tubes, 64 channels each, for...
We present the new insight into our ongoing mass composition analysis based on KASCADE archive data using deep neural networks. The archive consists of ~300M air shower events detected by a 16x16 array of scintillating detectors and spans from 1996 to 2013. Our goal is to reconstruct the initial particle from that data accurately. We introduced five mass groups; thus, the reconstruction...
The investigation of the energy spectrum and the mass composition of cosmic rays in the 1 TeV - 1 PeV energy range is an important topic in astroparticle physics, as it can provide clues to understand the origin, acceleration mechanism and propagation of high-energy cosmic rays in our galaxy, as well as to find out the link between the TeV and the PeV cosmic-ray radiation. At HAWC, extensive...
The HAWC observatory is an air shower detector well suited for the research of cosmic rays in the energy interval between 10 TeV to 1 PeV , which is very interesting because in this range the data from space-borne detectors and extensive air shower experiments overlap. This fact opens the possibility to perform cross checks between direct and indirect cosmic ray detector techniques and to...
Lorentz Invariance Violation (LIV) can be studied in various sectors of
high-energy particle physics. Since its effects are predicted to
increase with energy, ultra-high energy cosmic rays and gamma rays are
powerful probes for testing different LIV models. In this work, the
unprecedented statistics and data quality collected by the Pierre Auger
Observatory in the EeV range are used to...
The Pierre Auger Observatory is the largest astroparticle experiment in operation. Complementing to the measurements of the charged ultra-high energy (UHE) cosmic rays, it has a very good sensitivity to the detection of photons and neutrinos. Since the UHE photon and neutrino fluxes are correlated to the acceleration mechanisms of charged particles, searches for these neutral particles enhance...
To find and understand the sources of ultra-high-energy cosmic rays necessitates to measure the properties of these particles with high precision. One of the objectives of the upgrade of the Pierre Auger Observatory is to increase in particular the mass sensitivity of the observatory and to identify the particle types with unprecedented precision. Part of this upgrade is the Radio Detector...
In 2021 the first three stations of the Radio Neutrino Observatory Greenland (RNO-G) have been deployed, consisting of in-ice strings of antennas down to 100 meters and antennas just below the surface. Apart from measuring ultra high energy neutrinos, RNO-G will be able to detect cosmic rays with a total effective area of close to ~100km\textsuperscript{2} above 0.1 EeV. Air showers are an...
We present first steps of the search for ultra-high-energy (> PeV) gamma rays based on archival data acquired by the KASCADE experiment.
This one operated from 1996 to 2013 and the collected statistics is comparable with those of modern ovservatories. The data is provided by the KASCADE Cosmic ray Data Center (KCDC) and public accessible.
Since the signatures left by gamma rays and...
Surface detector arrays sample the distribution of particles from extensive air showers arriving at the ground. For a shower arriving from the zenith and for a flat array, this distribution is effectively radially symmetric. For inclined showers, however, detectors sample the shower at different stages in its development. Together with related attenuative and geometric effects, this results in...
Supernova Remnants (SNRs) are considered as the primary sources of galactic cosmic
rays (CRs), where CRs are assumed to be accelerated by diffusive shock acceleration (DSA) mechanism, specifically at SNR shocks. In the core-collapse scenario, the SNR shocks expand inside the complex ambient environment as the core-collapse SNRs have massive progenitor stars (
Recent theoretical and numerical studies incorporating cosmic rays (CRs) into global modelling of magnetized interstellar medium demonstrate that CRs can play an important role in the generation of large-scale galactic magnetic fields and, at the same time, in driving galactic winds. Cosmic-Ray-driven dynamos produce magnetic arms in galactic disks and large-scale helical magnetic fields in...
The magnetorotational instability (MRI) is believed to generate the MHD turbulence necessary for efficient outward angular momentum transport in various black hole accretion disks. In low-luminosity accreting black holes, the density in the accreting plasma is so small that particle-particle Coulomb collisions occur very infrequently, making these disks effectively โcollisionlessโ. These...
Pulsars dominate the local cosmic-ray positron flux at high energies by producing electron-positron pairs from their spindown energy. While the AMS-02 experiment, that measures the cosmic-ray flux to great precision, shows that the positron flux is very smooth, simple simulations of pulsar models predict sharp spectral features. In this work, we add several mechanisms to model the local...
Star-forming galaxies are known to have been abundant at redshifts above z~6, and recent observations have revealed examples of high redshift primordial galaxies with evolved stellar populations and complex star-formation histories (SFHs) spanning into the first 250 Myr after the Big Bang. In these systems, intense bursts of star-formation appear to be interspersed with sustained periods of...
Active Galactic Nuclei (AGNi) can launch and sustain powerful outflows of very high velocity and large opening angle.
Provided that the activity lasts long enough such outflows develop a bubble structure characterized by an inner wind shock and an outer forward shock.
During the time the forward shock expands in the surrounding medium, the inner wind shock quickly decelerates while remaining...
Very High Energy Cosmic Rays are believed to be accelerated in astrophysical jets. The formation of such jets requires spinning black holes. Therefore, the modeling of spinning black holes is a fundamental diagnostics for Cosmic Ray acceleration. However, detecting spinning black holes is still a difficult task. The detectability largely depends on high-quality data and very importantly on...
The cosmic-ray fluxes of electrons and positrons (
Current measurements of cosmic-ray fluxes have reached unprecedented accuracy thanks to the new generation of experiments, and in particular the AMS-02 mission. At the same time, significant progress has been made in the propagation models of galactic cosmic rays. These models include several propagation parameters, which are usually inferred from the ratios of secondary to primary cosmic...
The AMS-02 detector on board the International Space Station provides precise measurements of high-energy galactic cosmic rays (CRs) near Earth, while the Voyager mission measures CRs outside the solar system, beyond the effects of solar modulation. Observations of CRs by Voyager and AMS-02 provide valuable information on the propagation of CRs in the galaxy. Here we present a revision of...
Cosmic-ray feedback is suspected to affect star formation in molecular clouds by providing pressure support comparable to the thermal and magnetic ones. Thanks to numerical simulations, this extra support is known to drive galactic winds and thicken the galactic disc. The feedback efficiency, however, depends on CR transport properties which locally vary with interstellar turbulence, gas...
The paths of cosmic rays are deflected upon passing through the Galactic magnetic field structure. The strength of the deflections that these cosmic rays undergo is dependent on the strength and structure of the Galactic magnetic field. Unfortunately, our knowledge of the Galactic magnetic field is very limited, especially when considering the fields present in the Galactic halo region. In...
The expected level of correlations between the position in the sky of the sources of ultra-high-energy cosmic rays (UHECRs) and their actual arrival directions at Earth depends on the strength of the magnetic fields governing their propagation and the density of the sources. We investigate which combinations of magnetic-field setups and source densities can explain the recently observed...
The ฮณ-ray emission from stars is induced by the interaction of cosmic rays with stellar atmospheres and photon fields. This emission is expected to come in two components: a stellar disk emission, where ฮณ-rays are mainly produced in atmospheric showers generated by hadronic cosmic rays, and an extended halo emission, where the high density of soft photons in the surroundings of stars create a...
The transport of charged particles in various astrophysical environments permeated by magnetic fields is described in terms of a diffusion process, which relies on diffusion-tensor parameters generally inferred from Monte Carlo simulations. In this contribution, a theoretical derivation of the diffusion coefficients is presented. The approach, based on a few approximations to model the 2-point...
The creation of anti-nuclei in the Galaxy has been has been discussed as a possible signal of exotic production mechanisms such as primordial black hole evaporation or dark matter decay/annihilation in addition to the more conventional production from cosmic-ray (CR) interactions with the gas in the interstellar medium. Excitingly, other astrophysical excesses that have been correlated with...
Analysis of anisotropy of the arrival directions of galactic protons, helium, carbon and oxygen has been performed with the Alpha Magnetic Spectrometer on the International Space Station. These results allow to investigate the origin of the spectral hardening observed by AMS in these cosmic ray species. The AMS results on the dipole anisotropy are presented along with the discussion of the...
Cosmic Rays (CR) inside the Heliosphere interact with the solar wind and with the interplanetary magnetic field, resulting in a temporal variation of the cosmic ray intensity near Earth for rigidities up to a few tens of GV. This variation is known as Solar Modulation. Previous AMS results on proton and helium spectra showed how the two fluxes behave differently in time. To better understand...
We present RDSim, a fast and comprehensive framework for the simulation of the radio detection of downgoing air showers. It can handle any downgoing shower that can be simulated with ZHAireS, including those induced by CC and NC neutrino interactions and
O Deligny1, I Lhenry-Yvon1, Q Luce2, M Roth2, D Schmidt2 and A A Watson3
1 IJClab (Laboratoire de Physique des 2 Infinis Irรจne Joliot-Curie), CNRS/IN2P3, Universitรฉ Paris-Saclay, Orsay, France 2 Institut fรผr Astroteilchenphysik (IAP), Karlsruhe Institute of...
Simulations of extensive air showers using current hadronic interaction models predict too small number of muons compared to events observed in the air shower experiments, which is known as the muon deficit problem. In this work, we present a new method to calculate the factor by which the muon signal obtained via Monte-Carlo simulations must be rescaled to match the data, as well as the ฮฒ...
The predictions of high energy hadronic interaction models for hadron induced air showers contain significant systematic uncertainties due to the limits of both accelerator data and theoretical descriptions in the appropriate energy and rapidity ranges. Tuning for these models is typically performed to reproduce cosmic-ray data above 10
We present a novel semi-analytical treatment of the radio emission of air showers that is able to reproduce the results of full ZHAireS simulations, in theory at a fraction of the computational cost. Traditionally, the contribution to the vector potential of every single particle track in the shower is calculated separately. Instead, in our approach we divide the air shower into 4-D spacetime...
The Fortran-versions of the CORSIKA air shower simulation code have been at the core of simulations for many astroparticle physics experiments for the last 30 years. Having grown over decades into an ever more complex software, maintainability of CORSIKA has become increasingly difficult, though its performance is still excellent. Since 2018, therefore a complete rewrite of CORSIKA has begun...
The study of cosmic-ray (CR) composition plays an important role in determining their origin and acceleration mechanism. In the TeV energy range, space experiments perform composition measurements that identify incoming particles and measure the energy accurately. Ground-based experiments can provide a complementary measurement of the mass composition by studying air showers. The depth of the...
