Showing papers by "Abigail G. Vieregg published in 2023"
1 citations
15 Feb 2023
TL;DR: The Radio Neutrino Observatory Greenland (RNO-G) as discussed by the authors detects in-ice radio waves emitted by neutrino induced particle showers in the Greenlandic ice sheet.
Abstract: In the ultra-high-energy (UHE) regime, the low predicted neutrino fluxes are out of reach for currently running neutrino detectors. Larger instrumented volumes are needed to probe these low fluxes. The Radio Neutrino Observatory Greenland (RNO-G) detects in-ice radio waves emitted by neutrino induced particle showers in the Greenlandic ice sheet. Radio waves have a large attenuation length ($\sim$1km), and therefore RNO-G implements a sparse instrumentation to cover an unprecedented volume. By 2022, seven stations have been deployed, consisting of a deep in-ice component and antennas just below the surface. Apart from measuring UHE neutrinos, RNO-G will be able to detect cosmic-ray air showers with a total effective area of close to $\mathcal{O}$(100km$^2$) above 0.1 EeV. Detected air showers can be used as a source for in-situ calibration of the detector and provide an important verification measurement due to the possible backgrounds. Prospects for in-ice signal detection of air showers are developing further: Simulations suggest energy dense cores which propagate though the ice and are visible to deep antennas. In addition, catastrophic energy losses from high energy air shower muons penetrating the ice may mimic the interaction of a neutrino. An efficient surface trigger will provide a veto mechanism for both types of events. The collected data of shallow and deep antennas can be used to verify simulations for in-ice development of air showers. This contribution introduces RNO-G, discusses lessons learned from the first year of data taking and outlines possible backgrounds.
TL;DR: The Beamforming Elevated Array for COsmic Neutrinos (BEACON) as mentioned in this paper is a novel detector concept that utilizes a mountaintop radio interferometer to search for the radio emission due to these extensive air showers.
Abstract: When ultrahigh energy tau neutrinos skim the Earth, they can generate tau leptons that then decay in the atmosphere, forming upgoing extensive air showers. The Beamforming Elevated Array for COsmic Neutrinos (BEACON) is a novel detector concept that utilizes a mountaintop radio interferometer to search for the radio emission due to these extensive air showers. The prototype, located at the White Mountain Research Station in California, consists of 4 custom crossed-dipole antennas operating in the 30-80 MHz range and uses a directional interferometric trigger to achieve reduced thresholds and background rejection. The prototype will first be used to detect extensive air showers from down-going cosmic rays to validate the detector model. In this talk, we give an overview of the BEACON concept and the status of its prototype. We also discuss the ongoing cosmic ray search which utilizes both data analysis and simulation.
12 Apr 2023
TL;DR: In this paper , the authors used data from the nearby GISP2 and GRIP ice cores to determine the index of refraction of the bulk ice as n=1.778 +/- 0.006.
Abstract: Glacial ice is used as a target material for the detection of ultra-high energy neutrinos, by measuring the radio signals that are emitted when those neutrinos interact in the ice. Thanks to the large attenuation length at radio frequencies, these signals can be detected over distances of several kilometers. One experiment taking advantage of this is the Radio Neutrino Observatory Greenland (RNO-G), currently under construction at Summit Station, near the apex of the Greenland ice sheet. These experiments require a thorough understanding of the dielectric properties of ice at radio frequencies. Towards this goal, calibration campaigns have been undertaken at Summit, during which we recorded radio reflections off internal layers in the ice sheet. Using data from the nearby GISP2 and GRIP ice cores, we show that these reflectors can be associated with features in the ice conductivity profiles; we use this connection to determine the index of refraction of the bulk ice as n=1.778 +/- 0.006.
TL;DR: The Radio Neutrino Observatory in Greenland (RNO-G) is an in-ice radio detector for ultra-high energy neutrinos with the potential to make the first detection of a neutrino shower beyond $\sim$10 PeV via the Askaryan emission as mentioned in this paper .
Abstract: The Radio Neutrino Observatory in Greenland (RNO-G) is an in-ice radio detector for ultra-high energy neutrinos with the potential to make the first detection of a neutrino shower beyond $\sim$10 PeV via the Askaryan emission. With a projected 90\% CL upper limit below $E^2\Phi \approx10^{-8}$GeV/cm$^2$/s/sr within 10 years of operation, RNO-G will reach realistic models of GZK and astrophysical neutrino fluxes. In 2021, the first three stations of RNO-G were installed and started data-taking. Four additional stations were added in 2022 with some upgrades to the station hardware. Here, we present the current status of the instrument and give an overview of the efforts towards calibration and analysis of the data recorded so far.
09 Jul 2023
TL;DR: In this paper , the authors investigate potential correlations between IceCube's neutrino events and the Fermi and MOJAVE source catalogs, using the publicly-available IceCube data set.
Abstract: The origin of the diffuse astrophysical neutrino flux measured by the IceCube Observatory remains largely unknown. Although NGC 1068 and TXS 0506+056 have been identified as potential neutrino sources, the diffuse flux of neutrinos must have additional sources that have not yet been identified. Here we investigate potential correlations between IceCube's neutrino events and the Fermi and MOJAVE source catalogs, using the publicly-available IceCube data set. We perform three separate spatially-dependent, energy-dependent, and time-dependent searches, and find no statistically significant sources outside of NGC 1068. We find that no more than 13% of IceCube's neutrino flux originates from blazars over the whole sky. Then, using an energy-dependent likelihood analysis, the limit on neutrinos originating from blazars reduces to 9% in the Northern hemisphere. Finally, we set limits on individual sources from the MOJAVE radio catalog after finding no statistically significant time-flaring sources.
TL;DR: In this article , the current status of the analysis targeting the detection of cosmic-rays induced air showers is presented, which includes the presentation of a method to create a complete template set and a first look at RNO-G data.
Abstract: The Radio Neutrino Observatory – Greenland (RNO-G) is an in-ice neutrino detector, using radio emission to target the first measurement of neutrinos beyond PeV energies. In total 35 stations are planned for the detector, resulting in a detection volume of around 100 $\mathrm{km}^3$. Each of these stations is equipped with deep antennas embedded $\sim$ 100 m into the ice and downward-pointing log-periodic dipole antennas (LPDA) buried $\sim$ 3 m into the snow. At each station, three additional buried LPDA are pointing towards the sky and thus can be used to look for cosmic-ray induced air-showers. These air showers are a background for the RNO-G detector and therefore important to understand, but they also can be used as a calibration tool. In order to find the air-shower signals, we apply an analysis based on template matching to the data. We present the current status of the analysis targeting the detection of cosmic-rays induced air showers. This includes the presentation of a method to create a complete template set and a first look at RNO-G data.