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Understanding the nanoscale organization of natural killer cell receptor NKp30 at the singlemolecule level
No full textSearches for UHE neutrinos and upward-going showers at the Pierre Auger Observatory
Get PDFThe Pierre Auger Observatory, as a key actor in multi-messenger astronomy, is playing a crucial role in searching for and following-up cosmic phenomena across different channels. Data from the Observatory have been utilized for nearly 20 years to search for showers induced by Ultra-High-Energy (UHE) neutrinos with energies exceeding 0.1 EeV. Neutrino-induced showers at high zenith angles are likely to develop deep in the atmosphere, resulting in a significant electromagnetic component that distinguishes them from the cosmic-ray background. This enables the identification of candidate events from both neutrinos interacting in the atmosphere and Earth-skimming τ neutrinos. Searches have been conducted for both diffuse and point sources using data collected by the Surface Detector, a large array of over 1660 water-Cherenkov stations spread over an area of 3000 square km. Additionally, the Fluorescence Detector consisting of 27 telescopes has been employed to search for upward-developing air showers, as predicted by several interpretations of the \u27anomalous\u27 events detected by the ANITA detector. In this contribution, we summarize the main results obtained in these searches and discuss their astrophysical implications
Testing the declination dependency of the spectrum measured by the Pierre Auger Observatory
Get PDFThe distribution of the arrival directions of cosmic rays observed by the Pierre Auger Observatory has a dipolar component that implies a flux dependence on declination. Previously, we showed that the spectrum built from events arriving with a zenith angle less than 60° is qualitatively consistent with the dipole. In this work, we go one step further and show that the Auger spectrum cannot reject the hypothesis of a declination-independent flux. By using events of up 80°, we extend the previous survey from +25° of declination to +45°, thus covering 85% of the sky
Calibrating the Surface Scintillator Detector of AugerPrime
Get PDFWe present the methods used to calibrate the Surface Scintillator Detector of the Pierre Auger
Observatory. We describe how to obtain an accurate calibration of the scintillator by examining
peak and charge distributions of atmospheric muons. This is done whenever an extensive air
shower event measured by the Surface Detector is reconstructed. We also describe the work
towards an algorithm that uses a rate-based approach to calibrate the Surface Scintillator
Detectors independently
The Radio Detector of the Pierre Auger Observatory
Get PDFTo measure the properties of the highest-energy particles in the Universe with unprecedented precision, we have upgraded the Pierre Auger Observatory. A crucial component of this upgrade is the Radio Detector. Radio antennas have been added to all 1660 positions of the surface detector array, covering an area of 3000 sq. km. The antennas detect radio emission, emitted by extensive air showers in the frequency band from 30 to 80 MHz in two polarization directions - one parallel and one perpendicular to the Earth magnetic field. For inclined air showers with zenith angles above 60 degrees, the radio antennas provide a clean measurement of the electromagnetic shower component, while the water-Čerenkov detectors measure the muonic component. Large-scale deployment in the Argentinian Pampa Amarilla started around June 2023 and has been completed in 2024. The deployment is accompanied by extensive calibration efforts both, in the laboratory and in the field. The signal chain is characterized in the laboratory. Galactic radio emission is used as a reference signal and the antenna patterns are verified through in-situ calibrations with a reference antenna. Commissioning of the system is in full progress as well as the analysis of first measured air showers. We present first air showers measured with the largest radio detector for cosmic rays in the world
