Speaker
Description
The origin of cosmic rays has been one of the motivating questions of the astrophysics field for over a century, an open and exciting topic since then. To help answer this question, the Pierre Auger Observatory investigates the anisotropies of the ultra-high-energy cosmic rays (UHECRs) — with energies above ${\sim}32$${\,}$PeV — at small, intermediate, and large angular scales. The Observatory has been collecting data for over 19 years, reaching more than 135${\,}$000${\,}$km$^2$${\,}$yr${\,}$sr of accumulated exposure, with the surface detectors spread over 3000${\,}$km$^2$. So far, the most significant discovery is a large-scale dipole structure with a total amplitude of approximately 7%. This results from the observed modulation in right ascension in the inclusive energy bin above 8${\,}$EeV, where the computed dipole equatorial component has a statistical significance of over 5$\sigma$. In this contribution, we present the latest updates on anisotropy searches. In addition to the limits on modulation in right ascension constrained from ${\sim}32$${\,}$PeV to ${\geq}32$${\,}$EeV, the results outlined in this presentation include catalog-based and overdensity searches, with a reported excess around the Centaurus region. Finally, we discuss the prospects of anisotropy searches in light of mass-composition information of Phase II of the Pierre Auger Observatory, AugerPrime.
