The average profiles of cosmic ray shower development as a function of atmospheric depth are measured for the first time with the Fluorescence Detectors at the Pierre Auger Observatory. The profile shapes are well reproduced by the Gaisser-Hillas parametrization at the 1% level in a 500 g/cm2 interval around the shower maximum, for cosmic rays with log(E/eV) > 17.8. The results are quantified with two shape parameters, measured as a function of energy. The average profiles carry information on the primary cosmic ray and its high energy hadronic interactions. The shape parameters predicted by the commonly used models are compatible with the measured ones within experimental uncertainties. Those uncertainties are dominated by systematics which, at present, prevent a detailed composition analysis.
In 2018, the IceCube collaboration reported evidence for the identification of a blazar as an astrophysical neutrino source. That evidence is briefly summarised here before focusing on the prospects of tau neutrino physics in IceCube, both at high energies (astrophysical neutrinos) and at lower energies (atmospheric neutrino oscillations). In addition, future neutrino detectors such as KM3NeT and the IceCube Upgrade and their tau neutrino physics potential are discussed. Finally, the detection mechanism for high-energy (tau) neutrinos in the Pierre Auger Observatory and the resulting flux uppe…
The hybrid design of the Pierre Auger Observatory allows for the measurement of a number of properties of extensive air showers initiated by ultra-high energy cosmic rays. By comparing these measurements to predictions from air shower simulations, it is possible to both infer the cosmic ray's mass composition and test hadronic interactions beyond the energies reached by accelerators. In this paper, we will present a compilation of results of air shower measurements by Pierre Auger Observatory which are sensitive to the properties of hadronic interactions and can be used to constrain the hadron…
I describe some of the results on ultrahigh-energy cosmic rays that have been obtained with the Pierre Auger Observatory. These include measurements of the spectrum, composition and anisotropies. Possible astrophysical scenarios that account for these results are discussed.
Ultra High Energy Cosmic Rays are the most energetic particles directly measured, reaching orders of magnitude above those attained in the LHC. The Pierre Auger Observatory is shedding light onto the long-standing mysteries of their nature and origin. The present paper briefly reviews the latest results: the energy spectrum and mass composition of UHECR, limits on the fluxes of photons and neutrinos, the study of anisotropies in the arrival directions of UHECS, and finally the constraints on high energy hadronic models. The paper will finish with the upgrade of the Observaotry: AugerPrime.
The characteristics of an extensive air shower derive from both the mass of the primary ultra-high-energy cosmic ray that seeds its development and the properties of the hadronic interactions that feed it. With its hybrid detector design, the Pierre Auger Observatory measures both the longitudinal development of showers in the atmosphere and the lateral distribution of particles arriving at the ground, from which a number of parameters are calculated and compared with predictions from current hadronic interaction models tuned to LHC data. At present, a tension exists concerning the production …
While the Pierre Auger Observatory is a very successful instrument for ultra-high energy cosmic ray (UHECR) detection, it is increasingly used as part of various types of multi-messenger searches, in which it contributes with searches for air showers induced by atomic nuclei, neutrons, photons, and neutrinos. We present an overview of the multi-messenger activities of the Pierre Auger Observatory. The overview includes: searches for ultra-high energy photons and neutrinos detected by the Pierre Auger Observatory in coincidence with gravitational wave events detected by LIGO and Virgo; searches…
The Pierre Auger Observatory has by now achieved an exposure of order $10^5~{\rm km}^2$ sr yr, exploring about 85% of the sky. In this talk, I will review some of the recent results, including the detailed measurements of the features in the cosmic ray spectrum, the study of the anisotropies in the cosmic ray arrival directions both at large and intermediate angular scales, the inferred mass composition, and multimessenger searches.
The Pierre Auger Observatory is the largest facility in the world to study ultra-high-energy cosmic rays. It has a hybrid detection technique that combines the observation of the longitudinal development of extensive air showers and the measurement of their particles at the ground. This capability has opened the possibility to probe hadronic interactions taking place at energies well beyond those accessible by human-made accelerators. In this report, we present a selection of the latest results on hadronic interactions with measurements from the Pierre Auger Observatory. These data span over t…
Search for a correlation between ANTARES neutrinos and Pierre Auger Observatory UHECRs arrival directions
对ANTARES望远镜2007-2008年探测到的2190个中微子候选事件和Pierre Auger天文台2004年1月1日至2009年12月31日观测到的69条超高能宇宙射线（UHECR）的到达方向进行了相关性研究。相应的90% C.L.来自每个观测到的UHECR方向的中微子通量的上限（假设来自所有方向的通量相等，并且对于$E^{-2}$能谱）为4.99 $\times10{^{-8}}$ GeV cm $^{-2}$ s $^{-1}$。
The Pierre Auger Observatory is the largest extensive air shower detector. Based on a hybrid system, this experiment measures the longitudinal shower development and the particles at the ground. This detection system allows the extraction of the p-air cross-section at energies much higher than the ones accessible by current colliders. It is also possible to test hadronic interaction models using correlations between different air shower observables, like the depth of shower maximum and the muon number at the ground and their fluctuations. Thanks to the low energy extension of the Pierre Auger …
In this paper some recent results from the Pierre Auger Collaboration are presented. These are the measurement of the energy spectrum of cosmic rays over a wide range of energies ($10^{17.5}$ to above $10^{20}$ eV), studies of the cosmic-ray mass composition with the fluorescence and surface detector of the Observatory, the observation of a large-scale anisotropy in the arrival direction of cosmic rays above 8 x $10^{18}$ eV and indications of anisotropy at intermediate angular scales above 4 x $10^{19}$ eV. The astrophysical implications of the spectrum and composition results are also discus…
Over the past decade the multi-messenger astrophysics has emerged as a distinct discipline, providing unique insights into the properties of high-energy phenomena in the Universe. The Pierre Auger Observatory, located in Malargüe, Argentina, is the world's largest cosmic ray detector sensitive to photons, neutrinos, and hadrons at ultra-high energies. Using its data, stringent limits on photon and neutrino fluxes at EeV energies have been obtained. The collaboration uses the excellent angular resolution and the neutrino identification capabilities of the Observatory for follow-up studies of ev…
The scientific achievements of the Pierre Auger Collaboration cover diverse and complementary fields of research. The search for the origin of ultra-high energy cosmic rays (UHECRs) is based on the measurement of the energy spectrum and mass composition of the primaries, on studies of multi-messengers, and on extensive anisotropy searches. With the collected data it is also possible to explore the characteristics of hadronic interactions at energies unreachable at human-made accelerators, and to assess the existence of non-standard physics effects. A selection of the latest results is presente…
In this paper, the connection between Pierre Auger Observatory measurements and photons is discussed. Three cases are presented: the search for photons in the ultrahigh-energy cosmic-ray radiation, the impact of the photon background in the cosmic ray propagation and the role of the ambient photon fields surrounding cosmic accelerators.
Using data collected at the Pierre Auger Observatory, we search for signatures of instanton-induced processes that would provide evidence of super-heavy particles decaying in the Galactic halo. Such particles could have been produced sufficiently during the post-inflationary epoch to match the relic abundance of dark matter inferred today. The non-observation of these signatures allows us to probe the instanton strength and to derive a bound, the best ever obtained from instanton-mediated processes, on the reduced coupling constant of gauge interactions in the dark sector: $α_X \lesssim 0.09$,…
The IceCube Neutrino Observatory, the Pierre Auger Observatory and the Telescope Array: Joint Contribution to the 35th International Cosmic Ray Conference (ICRC 2017)
Ultra-high-energy cosmic rays (UHECRs) are studied with giant ground-based detector systems recording extensive air showers, induced by cosmic ray particles in the atmosphere. Research at the Pierre Auger Observatory - the largest of such detectors ever built -- largely contributed to a number of breakthroughs and dramatically advanced our understanding of UHECRs. Nonetheless, the results so far are still inconclusive as neither have the sources of these most energetic particles known in the Universe been determined, nor has the origin of the unambiguously established cosmic ray flux suppressi…
