The ARIANNA Hexagonal Radio Array – performance and prospects

Abstract

Abstract. The origin of the highest energy cosmic rays at ∼10 20 eV is still unknown. Ultra-high energy neutrinos from the GZK process should provide information on the sources and their properties. A promising and cost effective method for observing GZKneutrinos is based on detection of Askaryan radio pulses with antennas installed in ice. The ARIANNA project aims at instrumenting a 36*36 km 2 large area on the Ross Ice Shelf with an array of radio detection stations. The deployment of a test system for ARIANNA, the Hexagonal Radio Array (HRA), was completed in December 2014. The three first stations were installed in 2012. Solar panels are used to drive the < 10 W stations. The system hibernated at sunset in April and all stations returned to operation in September. The site is essentially free of anthropogenic noise. Simple cuts eliminate background and provides for efficient selection of neutrino events. Prospects for the sensitivity of the full ARIANNA array to the flux of GZK neutrinos are shown.

Probing the Extragalactic Cosmic-Ray Origin with Gamma-Ray and Neutrino Backgrounds

“…4 shows the resulting ν spectra for different EGCR models, together with the sensitivity of current and planned experiments. The mixed-composition models predict ν fluxes too low to be detected by IceCube (Aartsen et al 2016) or ARIANNA (Hallgren 2016), even in the case of a GRB-like cosmological evolution. They would require a sensitivity such as that expected for the GRAND observatory (Martineau-Huynh et al 2015) or CHANT satellite concept (Neronov et al 2016).…”

“…Only very strong evolutions are excluded by the current observations. (Aartsen et al 2016) and the expected sensitivities of ARIANNA (5 years, 50 MHz option, Hallgren (2016)) and GRAND (3 years, Martineau-Huynh et al (2015)). Lower panel: same, i) for 100% proton scenarios compatible with the Fermi constraints (plain lines, same colour code), and ii) for a sub-dominant proton component (contributing 5% of the UHECRs at 10 EeV) evolving as FR-II galaxies (dashed-dotted line) (Wall et al 2005).…”

Progress in the Development of Radio-Cherenkov Neutrino Detectors

“…In an exposure time of 10 months, ARA reported a flux limit of 3x10 -6 GeV cm -2 s -1 sr -1 at 10 18 eV from two stations. By comparison, in 4 months since commissioning HRA pilot array in December 2014, the ARIANNA collaboration reported a preliminary flux limit a factor of 4 larger [42]. Both results…”

“…One of the major objectives of the ARIANNA and ARA37 pilot programs is to establish firm estimates for detector sensitivity under realistic conditions since this value relies on operating parameters such as analysis efficiency and livetime. Recent publications by both the ARA [15] and ARIANNA [14] collaborations and preliminary results from the completed Hexagonal Radio Array ( HRA, the pilot array of ARIANNA) [42] can be used to make a detailed comparison of the two techniques. ARA released results from two of three deep stations that ran in 2013 (one of the three deployed stations has not provided data since that time and so it was not included in the analysis) and the ARIANNA collaboration provided data from HRA, completed in December 2014, which corroborated results from an earlier investigation using data from the first three stations deployed in 2012.…”