122281285
Ultra-high-energy cosmic ray and neutrino detection using the Moon
When Ultra-high-energy (UHE) neutrinos or cosmic rays interact in the lunar surface they will initiate a particle cascade. These cascades have a sizeable negative charge excess and radiate coherent Cherenkov radio emission in a process known as the Askaryan effect. The optimal frequency window for observing these pulses with radio telescopes on the Earth lies around 150 MHz. With 47.6 hours of observation time with the Westerbork Synthesis Radio Telescope array we are able to set a limit on the UHE neutrino as well as the UHE cosmic-ray flux. In the near future, the digital radio array LOFAR will be used to achieve an even lower limit.
117844015
The endpoint formalism for the calculation of electromagnetic radiation and its applications in astroparticle physics
We present the "endpoint" formalism for the calculation of electromagnetic radiation and illustrate its applications in astroparticle physics. We use the formalism to explain why the coherent radiation from the Askaryan effect is not in general Cherenkov radiation, as the emission directly results from the time-variation of the net charge in the particle shower. Secondly, we illustrate how the formalism has been applied in the air shower radio emission code REAS3 to unify the microscopic and macroscopic views of radio emission from extensive air showers. Indeed, the formalism is completely universal and particularly well-suited for implementation in Monte Carlo codes in the time- and frequency-domains. It easily reproduces well-known "classical mechanisms" such as synchrotron radiation, Vavilov-Cherenkov radiation and transition radiation in the adequate limits, but has the advantage that it continues to work in realistic, complex situations, where the "classical mechanisms" tend to no longer apply and adhering to them can result in misleading interpretations.
119071284
Status report and future prospects on LUNASKA lunar observations with ATCA
Abstract LUNASKA (Lunar UHE Neutrino Astrophysics with the Square Kilometre Array) is a theoretical and experimental project developing the lunar Cherenkov technique for the next generation of giant radio-telescope arrays. Here we report on a series of observations with ATCA (the Australia Telescope Compact Array). Our current observations use three of the six 22 m ATCA antennas with a 600 MHz bandwidth at 1.2–1.8 GHz, analogue dedispersion filters to correct for the typical night-time ionospheric dispersion, and state-of-the-art 2 GHz FPGA-based digital pulse detection hardware. We have observed so as to maximise the UHE neutrino sensitivity in the region surrounding the galactic centre and to Centaurus A, to which current limits on the highest-energy neutrinos are relatively weak.
56239300
An air shower array for LOFAR: LORA
LOFAR is a new form of radio telescope which can detect radio emission from air showers induced by very high-energy cosmic rays. It can also look for radio emission from particle cascades on the Moon induced by ultra high-energy cosmic rays or neutrinos. To complement the radio detection, we are setting up a small particle detector array LORA (LOfar Radboud Air shower array) within an area of ~300 m diameter in the LOFAR core. It will help in triggering and confirming the radio detection of air showers with the LOFAR antennas. In this paper, we present a short overview about LORA and discuss its current status.
122673987
Coherent Cherenkov radio emission from EeV showers in dense media through thinned simulations
Abstract We explore the feasibility of applying “thinning techniques” to the simulation of EeV electromagnetic showers in ice, salt, and the regolith of the Moon. By comparing the results of thinned showers to full simulations, we show that thinning techniques keep a good level of accuracy in the relevant shower and radio observables, and allow a considerable reduction in computing time. We apply thinning techniques to the simulation of EeV electromagnetic showers including the Landau–Pomeranchuk–Migdal effect. Our study is of the utmost importance for the determination of the sensitivity to extremely energetic neutrinos of experiments looking for radiopulses in dense media.
118954604
LUNASKA simultaneous neutrino searches with multiple telescopes
ICRC 2011 : 32nd International Cosmic Ray Conference 11-18 August, Beijing, China, 11 augustus 2011
53048052
TANAMI Blazars in the IceCube PeV Neutrino Fields
ABSTRACT The IceCube Collaboration has announced the discovery of a neutrino ﬂux in excess of the atmospheric background. Due to thesteeply falling atmospheric background spectrum, events at PeV energies are most likely of extraterrestrial origin. We present themultiwavelength properties of the six radio brightest blazars positionally coincident with these events using contemporaneous data ofthe TANAMI blazar sample, including high-resolution images and spectral energy distributions. Assuming the X-ray to -ray emissionoriginates in the photoproduction of pions by accelerated protons, the integrated predicted neutrino luminosity of these sources is largeenough to explain the two detected PeV events. Key words. neutrinos – galaxies: active – quasars: general 1. Introduction The detection of neutrinos at PeV energies in excess of the at-mospheric background reported by the IceCube Collaboration(Aartsen et al. 2013; IceCube Collaboration 2013) has prompteda quest to identify their extraterrestrial sources. The two eventswith PeV energies (event 20, dubbed ‘Ernie’ and event 14,‘Bert’, hereafter E20 and E14), detected between May 2010 andMay 2012
181751932
Summary of the triggering, DAQ, and analysis working group
118614292
Upcoming neutrino oscillation experiments at Fermilab
Two experiments to investigate neutrino oscillations are now under construction at Fermilab. An overview of the experiments is given.
16680596
Ultraviolet, Optical and X-ray Observations of the Type 1a Supernova 2005am with Swift
We present ultraviolet and optical light curves in six broadband filters and grism spectra obtained by Swift's Ultraviolet/Optical Telescope for the Type Ia supernova SN 2005am. The data were collected beginning about 4 days before the B-band maximum, with excellent coverage of the rapid decline phase and later observations extending out to 69 days after the peak. The optical and near-UV light curve match well those of SN 1992A. The other UV observations constitute the first set of light curves shorter than 2500 A and allow us to compare the light curve evolution in three UV bands. One interesting feature is that the decay in the intermediate UVM2 band is shallower than in the filters on either side and may result from the bump in the interstellar extinction curve. The UV behavior of this and other low-redshift supernovae can be used to constrain theories of progenitor evolution or to interpret optical light curves of high-redshift supernovae. Using Swift's X-Ray Telescope, we also report the upper limit to SN 2005am's X-ray luminosity to be 6 × 1039 ergs s-1 in the 0.3-10 keV. This result is derived from 58 ks of exposure time spread out over 7 weeks beginning 4 days before the B-band maximum.
14135082
Projected XMM Vision for MCVs
The XMM satellite has a scientific payload of 3 EPIC and 2 RGS instruments which provide for both imaging and non-dispersive spectroscopy as well as medium-to-high resolution dispersive spectroscopy, in the soft to medium X-ray bands. The co-aligned OM adds the facility for simultaneous optical and UV studies. In this poster paper we describe the instrumental characteristics of XMM, comparing them to those of ASCA. We also forecast the expected X-ray spectra of a selection of both the Polars and Intermediate Polars by means of simulations based on ASCA model fits.