RESULTS FROM THE ANITA EXPERIMENT

2007 ◽  
Vol 22 (30) ◽  
pp. 2237-2246 ◽  
Author(s):  
◽  
ANDREA SILVESTRI ◽  
S. W. BARWICK ◽  
J. J. BEATTY ◽  
D. Z. BESSON ◽  
...  
Keyword(s):  
Neutrino Flux ◽  
High Energy ◽  
Long Duration ◽  
Order Of Magnitude ◽  
Successful Launch ◽  
Balloon Experiment ◽  
Antarctic Continent ◽  
The Antarctic ◽  
Prototype Instrument ◽  
Better Than

The ANtarctic Impulse Transient Antenna (ANITA) is the first long-duration balloon experiment designed to search and measure the flux of Greisen–Zapsepin–Kuzmin (GZK) neutrinos. We present new limits on neutrinos fluxes of astronomical origin from data collected with the successful launch of a 2-antenna prototype instrument, called ANITA-lite, that circled the Antarctic continent for 18.4 days in January 2004. We performed a search for Ultra-High-Energy (UHE) neutrinos with energies above 3 × 1018 eV . No excess events above the background expectation were observed and a neutrino flux following E-2 spectrum for all neutrino flavors, is limited to [Formula: see text] for 1018.5 eV < Eν < 1023.5 eV at 90% confidence level. The launch of ANITA is scheduled for December 2006. Looking beyond ANITA, we describe a new idea, called ARIANNA (Antarctic Ross Iceshelf ANtenna Neutrino Array), to increase the sensitivity for GZK neutrinos by one order of magnitude better than ANITA.

scholarly journals Simulation of blowing snow over the antarctic ice sheet

1998 ◽  
Vol 26 ◽  
pp. 203-206 ◽  
Author(s):  
Hubert Gallée
Keyword(s):  
Sea Level ◽  
Surface Friction ◽  
Atmospheric Model ◽  
Blowing Snow ◽  
Katabatic Winds ◽  
Order Of Magnitude ◽  
Antarctic Continent ◽  
Global Sea Level ◽  
Mesoscale Atmospheric Model ◽  
The Antarctic

A preliminary simulation of blowing snow over the Antarctic continent made with a mesoscale atmospheric model is presented. Sensitivity experiments show that the increase of surface friction arising in conjunction with blowing snow has a relatively more important impact on the dynamics of strong katabatic winds than previously supposed. Sublimation in blowing snow over the Antarctic continent also contributes to the global sea-level budget. It is found that this contribution is of the same order of magnitude as the estimated present sea-level rise.

scholarly journals Reflections on the anomalous ANITA events: the Antarctic subsurface as a possible explanation

2020 ◽  
Vol 61 (81) ◽  
pp. 92-98 ◽  
Author(s):  
Ian M. Shoemaker ◽  
Alexander Kusenko ◽  
Peter Kuipers Munneke ◽  
Andrew Romero-Wolf ◽  
Dustin M. Schroeder ◽  
...  
Keyword(s):  
Phase Inversion ◽  
Cosmic Ray ◽  
High Energy ◽  
Air Showers ◽  
Radio Signals ◽  
Subsurface Layers ◽  
Balloon Experiment ◽  
Antarctic Impulsive Transient Antenna ◽  
Sole Criterion ◽  
The Antarctic

AbstractThe Antarctic Impulsive Transient Antenna (ANITA) balloon experiment was designed to detect radio signals initiated by high-energy neutrinos and cosmic ray (CR) air showers. These signals are typically discriminated by the polarization and phase inversions of the radio signal. The reflected signal from CRs suffer phase inversion compared to a direct ‘tau neutrino’ event. In this paper, we study subsurface reflection, which can occur without phase inversion, in the context of the two anomalous up-going events reported by ANITA. It is found that subsurface layers and firn density inversions may plausibly account for the events, while ice fabric layers and wind ablation crusts could also play a role. This hypothesis can be tested with radar surveying of the Antarctic region in the vicinity of the anomalous ANITA events. Future experiments should not use phase inversion as a sole criterion to discriminate between down-going and up-going events, unless the subsurface reflection properties are well understood.

scholarly journals Results from the third flight of ANITA

2019 ◽  
Vol 216 ◽  
pp. 01009
Author(s):  
Abigail Vieregg
Keyword(s):  
Cosmic Rays ◽  
Radio Emission ◽  
High Energy ◽  
Neutrino Interaction ◽  
Air Showers ◽  
The Third ◽  
Long Duration ◽  
Antarctic Impulsive Transient Antenna ◽  
Ultra High Energy Neutrinos ◽  
The Antarctic

We summarize results from the third flight of the Antarctic Impulsive Transient Antenna (ANITA), a NASA long-duration balloon payload that searches for radio emission from the interactions of ultra-high-energy neutrinos and cosmic rays. ANITAIII was launched in December 2014 and flew for 22 days. We report the results from multipleanalyses of the data, which search for Askaryan radio emission from neutrinos interacting in the Antarctic ice as well as geomagnetic radio emission from extensive air showers (EASs) induced by cosmic rays or a tau lepton created in an in-earth tau neutrino interaction. In the most sensitive Askaryan neutrino search, we find one eventon a pre-unblinding background of 0:7−0:3+0.5. Across all searches, including a dedicated EAS search, we find a total of 28 EAS-like events. One of these events is consistent with an upward-traveling EAS, with a post-unblinding background estimate of ⪷10−2.

IceCube and the discovery of high-energy cosmic neutrinos

2016 ◽  
Vol 25 (14) ◽  
pp. 1630028 ◽  
Author(s):  
Francis Halzen
Keyword(s):  
Neutrino Flux ◽  
High Energy ◽  
Current Status ◽  
Muon Neutrinos ◽  
Neutrino Detector ◽  
Data Set ◽  
The Earth ◽  
Order Of Magnitude ◽  
Initial Discovery ◽  
Neutrino Astronomy

By transforming a cubic kilometer of natural Antarctic ice into a neutrino detector, the IceCube project created the opportunity to observe cosmic neutrinos. We describe the experiment and the complementary methods presently used to study the flux of the recently discovered cosmic neutrinos. In one method, events are selected in which neutrinos interacted inside the instrumented volume of the detector, yielding a sample of events dominated by neutrinos of electron and tau flavor. Alternatively, another method detects secondary muons produced by neutrinos selected for having traveled through the Earth to reach the detector, providing a pure sample of muon neutrinos. We will summarize the results obtained with the enlarged data set collected since the initial discovery and appraise the current status of high-energy neutrino astronomy. The large extragalactic neutrino flux observed points to a nonthermal universe with comparable energy in neutrinos, gamma rays and cosmic rays. Continued observations may be closing in on the source candidates. In this context, we highlight the potential of multimessenger analyses as well as the compelling case for constructing a next-generation detector larger in volume by one order of magnitude.

scholarly journals The Askaryan Radio Array

2012 ◽  
Vol 8 (S288) ◽  
pp. 115-122
Author(s):  
Kara D. Hoffman
Keyword(s):  
Neutrino Flux ◽  
Austral Summer ◽  
Cosmic Ray ◽  
High Energy ◽  
Pierre Auger Observatory ◽  
Ultra High Energy ◽  
Performance Requirements ◽  
Transparent Media ◽  
Order Of Magnitude ◽  
Cosmic Ray Flux

AbstractUltra high energy cosmogenic neutrinos could be most efficiently detected in dense, radio frequency (RF) transparent media via the Askaryan effect. Building on the expertise gained by RICE, ANITA and IceCube's radio extension in the use of the Askaryan effect in cold Antarctic ice, we are currently developing an antenna array known as ARA (The Askaryan Radio Array) to be installed in boreholes extending 200 m below the surface of the ice near the geographic South Pole. The unprecedented scale of ARA, which will cover a fiducial area of ≈ 100 square kilometers, was chosen to ensure the detection of the flux of neutrinos suggested by the observation of a drop in high energy cosmic ray flux consistent with the GZK cutoff by HiRes and the Pierre Auger Observatory. Funding to develop the instrumentation and install the first prototypes has been granted, and the first components of ARA were installed during the austral summer of 2010–2011. Within 3 years of commencing operation, the full ARA will exceed the sensitivity of any other instrument in the 0.1-10 EeV energy range by an order of magnitude. The primary goal of the ARA array is to establish the absolute cosmogenic neutrino flux through a modest number of events. This information would frame the performance requirements needed to expand the array in the future to measure a larger number of neutrinos with greater angular precision in order to study their spectrum and origins.

scholarly journals UPDATED LIMITS ON THE ULTRA-HIGH ENERGY (UHE) NEUTRINO FLUX FROM THE RICE EXPERIMENT

2006 ◽  
Vol 21 (supp01) ◽  
pp. 153-157 ◽  
Author(s):  
I. KRAVCHENKO ◽  
C. COOLEY ◽  
D. SECKEL ◽  
J. ADAMS ◽  
S. CHURCHWELL ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Neutrino Flux ◽  
High Energy ◽  
South Pole ◽  
Ultra High Energy ◽  
Dipole Antennas ◽  
Radio Frequency Radiation ◽  
The Antarctic ◽  
Detector Modeling ◽  
Frequency Radiation

The RICE experiment (Radio Ice Cherenkov Experiment) at South Pole consists of an array of dipole antennas designed to detect the coherent radio frequency radiation produced by neutrino-induced showers in the Antarctic ice. We report updated limits on the ultra-high energy neutrino flux, based on RICE data taken between 2000 and 2004. These limits also reflect improvements in Monte Carlo simulations and detector modeling.

scholarly journals Simulation of blowing snow over the antarctic ice sheet

1998 ◽  
Vol 26 ◽  
pp. 203-206 ◽  
Author(s):  
Hubert Gallée
Keyword(s):  
Sea Level ◽  
Surface Friction ◽  
Atmospheric Model ◽  
Blowing Snow ◽  
Katabatic Winds ◽  
Order Of Magnitude ◽  
Antarctic Continent ◽  
Global Sea Level ◽  
Mesoscale Atmospheric Model ◽  
The Antarctic

A preliminary simulation of blowing snow over the Antarctic continent made with a mesoscale atmospheric model is presented. Sensitivity experiments show that the increase of surface friction arising in conjunction with blowing snow has a relatively more important impact on the dynamics of strong katabatic winds than previously supposed. Sublimation in blowing snow over the Antarctic continent also contributes to the global sea-level budget. It is found that this contribution is of the same order of magnitude as the estimated present sea-level rise.

Lichens of the Oasis Molodyozhnyi and adjacent areas (Enderby Land, Antarctic)

2013 ◽  
Vol 47 ◽  
pp. 167-178 ◽  
Author(s):  
M. P. Andreev
Keyword(s):  
Liquid Water ◽  
Climate Conditions ◽  
Water Ice ◽  
Buellia Frigida ◽  
Antarctic Continent ◽  
Harsh Climate ◽  
The Antarctic ◽  
First Time ◽  
Lichen Flora

Lichen flora and vegetation in the vicinity of the Russian base «Molodyozhnaya» (Enderby Land, Antarctica) were investigated in 2010–2011 in details for the first time. About 500 specimens were collected in 100 localities in all available ecotopes. The lichen flora is the richest in the region and numbers 39 species (21 genera, 11 families). The studied vegetation is very poor and sparse, but typical for coastal oases of the Antarctic continent. The poorness is caused by the extremely harsh climate conditions, insufficient availability of liquid water, ice-free land, and high insolation levels. The dominant and most common lichens are Rinodina olivaceobrunnea, Amandinea punctata, Candelariella flava, Physcia caesia, Caloplaca tominii, Lecanora expectans, Caloplaca ammiospila, Lecidea cancriformis, Pseudephebe minuscula, Lecidella siplei, Umbilicaria decussata, Buellia frigida, Lecanora fuscobrunnea, Usnea sphacelata, Lepraria and Buellia spp.

scholarly journals Starburst galaxies strike back: a multi-messenger analysis with Fermi-LAT and IceCube data

2021 ◽  
Vol 503 (3) ◽  
pp. 4032-4049
Author(s):  
Antonio Ambrosone ◽  
Marco Chianese ◽  
Damiano F G Fiorillo ◽  
Antonio Marinelli ◽  
Gennaro Miele ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Gamma Ray ◽  
Neutrino Flux ◽  
Data Interpretation ◽  
Realistic Model ◽  
High Energy ◽  
Starburst Galaxies ◽  
Neutrino Factory ◽  
High Energy Cosmic Rays ◽  
Astrophysical Objects

ABSTRACT Starburst galaxies, which are known as ‘reservoirs’ of high-energy cosmic-rays, can represent an important high-energy neutrino ‘factory’ contributing to the diffuse neutrino flux observed by IceCube. In this paper, we revisit the constraints affecting the neutrino and gamma-ray hadronuclear emissions from this class of astrophysical objects. In particular, we go beyond the standard prototype-based approach leading to a simple power-law neutrino flux, and investigate a more realistic model based on a data-driven blending of spectral indexes, thereby capturing the observed changes in the properties of individual emitters. We then perform a multi-messenger analysis considering the extragalactic gamma-ray background (EGB) measured by Fermi-LAT and different IceCube data samples: the 7.5-yr high-energy starting events (HESE) and the 6-yr high-energy cascade data. Along with starburst galaxies, we take into account the contributions from blazars and radio galaxies as well as the secondary gamma-rays from electromagnetic cascades. Remarkably, we find that, differently from the highly-constrained prototype scenario, the spectral index blending allows starburst galaxies to account for up to $40{{\ \rm per\ cent}}$ of the HESE events at $95.4{{\ \rm per\ cent}}$ CL, while satisfying the limit on the non-blazar EGB component. Moreover, values of $\mathcal {O}(100\, \mathrm{PeV})$ for the maximal energy of accelerated cosmic-rays by supernovae remnants inside the starburst are disfavoured in our scenario. In broad terms, our analysis points out that a better modelling of astrophysical sources could alleviate the tension between neutrino and gamma-ray data interpretation.

Sign in / Sign up

Export Citation Format

Share Document