English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present measurements of the large-scale cosmic-ray anisotropies in rightascension, using data collected by the surface detector array of the PierreAuger Observatory over more than 14 years. We determine the equatorial dipolecomponent, $\vec{d}_\perp$, through a Fourier analysis in right ascension thatincludes weights for each event so as to account for the main detector-inducedsystematic effects. For the energies at which the trigger efficiency of thearray is small, the ``East-West'' method is employed. Besides using the datafrom the array with detectors separated by 1500 m, we also include data fromthe smaller but denser sub-array of detectors with 750 m separation, whichallows us to extend the analysis down to $\sim 0.03$ EeV. The most significantequatorial dipole amplitude obtained is that in the cumulative bin above 8~EeV,$d_\perp=6.0^{+1.0}_{-0.9}$%, which is inconsistent with isotropy at the6$\sigma$ level. In the bins below 8 EeV, we obtain 99% CL upper-bounds on$d_\perp$ at the level of 1 to 3 percent. At energies below 1 EeV, even thoughthe amplitudes are not significant, the phases determined in most of the binsare not far from the right ascension of the Galactic center, at $\alpha_{\rmGC}=-94^\circ$, suggesting a predominantly Galactic origin for anisotropies atthese energies. The reconstructed dipole phases in the energy bins above 4 EeVpoint instead to right ascensions that are almost opposite to the Galacticcenter one, indicative of an extragalactic cosmic ray origin.

Cosmic-ray anisotropies in right ascension measured by the Pierre Auger Observatory