Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV
Abstract
More than half a century after the discovery of ultra-high energy cosmic rays (UHECRs), their origin is still an open question. The study of anisotropies in the arrival directions of such particles is an essential ingredient to solve this puzzle. We update our previous analysis of large-scale anisotropies observed by the Pierre Auger Observatory using the latest data collected before the AugerPrime upgrade. We select events with zenith angles up to 80 degrees, implying a sky coverage of 85%, and energies above 4 EeV, for which the surface detector of the Observatory is fully efficient. Dipolar and quadrupolar amplitudes are evaluated through a combined Fourier analysis of the event count rate in right ascension and azimuth. The analysis is performed in three energy bins with boundaries at 4, 8, 16 and 32 EeV and two additional cumulative bins with energies above 8 and 32 EeV. The most significant signal is a dipolar modulation in right ascension for energies above 8 EeV, as previously reported, with statistical significance of 6.6σ. Additionally, we report the measurements of the angular power spectrum for the same energy bins with the same dataset.
Keywords
Pierre Auger Observatory;indirect detection;surface detection;ground array;ultra-high energy;cosmic rays;anisotropy;dipole;quadropole;angular power spectrum;inclined showers;
Data
| Language: | English |
|---|---|
| Year of publishing: | 2022 |
| Typology: | 1.08 - Published Scientific Conference Contribution |
| Organization: | UNG - University of Nova Gorica |
| UDC: | 539.1 |
| COBISS: |
166688515
|
| ISSN: | 1824-8039 |
| Views: | 31 |
| Downloads: | 0 |
| Average score: | 0 (0 votes) |
| Metadata: |
|
Other data
| Type (COBISS): | Not categorized |
|---|---|
| Pages: | str. 1-12 |
| Chronology: | 2022 |
| DOI: | 10.22323/1.395.0335 |
| ID: | 20029548 |
Recommended works:
Large-scale and multipolar anisotropies of cosmic rays detected at the Pierre Auger Observatory with energies above 4 EeV
2022,
no subtitle data available
ǂThe ǂultra-high-energy cosmic-ray sky above 32 EeV viewed from the Pierre Auger Observatory
2022,
no subtitle data available
TA SD analysis for inclined air showers
2023,
no subtitle data available
Update on the large-scale cosmic-ray anisotropy search at the highest energies by the Telescope Array experiment
2022,
no subtitle data available
ǂThe ǂupgrade of the Pierre Auger Observatory with the Scintillator Surface Detector
2022,
no subtitle data available