LUNASKA Experiment Observational Limits on UHE Neutrinos from Centaurus A and the Galactic Center

TL;DR

This paper reports the first observational limits on ultra-high energy neutrino fluxes from the Galactic Center and Centaurus A, using lunar radio detection methods with the ATCA, and compares these limits with theoretical models.

Contribution

It introduces new observational constraints on UHE neutrinos from specific astrophysical sources using the LUNASKA experiment at ATCA.

Findings

Established upper limits on UHE neutrino flux from the Galactic Center.

Established upper limits on UHE neutrino flux from Centaurus A.

Compared observational limits with models of cosmic ray origins.

Abstract

We present the first observational limits to the ultra-high energy (UHE) neutrino flux from the Galactic Center, and from Centaurus A which is the nearest active galactic nucleus (AGN). These results are based on our "Lunar UHE Neutrino Astrophysics using the Square Kilometer Array" (LUNASKA) project experiments at the Australia Telescope Compact Array (ATCA). We also derive limits for the previous experiments and compare these limits with expectations for acceleration and super-heavy dark matter models of the origin of UHE cosmic rays.