No Arabic abstract
One of the main objectives of the ANTARES telescope is the search for point-like neutrino sources. Both the pointing accuracy and the angular resolution of the detector are important in this context and a reliable way to evaluate this performance is needed. In order to measure the pointing accuracy of the detector, one possibility is to study the shadow of the Moon, i.e. the deficit of the atmospheric muon flux from the direction of the Moon induced by the absorption of cosmic rays. Analysing the data taken between 2007 and 2016, the Moon shadow is observed with $3.5sigma$ statistical significance. The detector angular resolution for downward-going muons is 0.73$^{circ}pm0.14^{circ}.$ The resulting pointing performance is consistent with the expectations. An independent check of the telescope pointing accuracy is realised with the data collected by a shower array detector onboard of a ship temporarily moving around the ANTARES location.
ANTARES is the largest undersea neutrino telescope and it has been taking data in its final configuration for more than ten years. On their journey to the Earth, cosmic rays can be absorbed by celestial objects, like the Sun, leading to a deficit in the atmospheric muon flux measured by the ANTARES detector, the so-called Sun shadow effect. This phenomenon can be used to evaluate fundamental telescope characteristics: the detector angular resolution and pointing accuracy. This work describes the study of the Sun shadow effect using the ANTARES data collected between 2008 and 2017. The statistical significance of the Sun shadow observation is $3.7sigma$ and the estimated angular resolution value of the ANTARES telescope for downward-going muons is $0.59^{circ} pm 0.10^{circ}$, which is consistent with the expectations obtained from the Monte Carlo simulations and also with the estimation from the Moon shadow analysis of 2007-2016 years. No evidence of systematic pointing shift is found and the resulting pointing accuracy is consistent with the expectations.
The ANTARES detector is an undersea neutrino telescope in the Mediterranean Sea. The search for point-like neutrino sources is one of the main goals of the ANTARES telescope, requiring a reliable method to evaluate the detector angular resolution and pointing accuracy. This work describes the study of the Sun shadow effect with the ANTARES detector. The shadow is the deficit in the atmospheric muon flux in the direction of the Sun caused by the absorption of the primary cosmic rays. This analysis is based on the data collected between 2008 and 2017 by the ANTARES telescope. The observed statistical significance of the Sun shadow detection is $3.7sigma$, with an estimated angular resolution of $0.59^circpm0.10^circ$ for downward-going muons. The pointing accuracy is found to be consistent with the expectations and no evidence of systematic pointing shifts is observed.
A search for cosmic neutrino sources using the data collected with the ANTARES neutrino telescope between early 2007 and the end of 2015 is performed. For the first time, all neutrino interactions --charged and neutral current interactions of all flavours-- are considered in a search for point-like sources with the ANTARES detector. In previous analyses, only muon neutrino charged current interactions were used. This is achieved by using a novel reconstruction algorithm for shower-like events in addition to the standard muon track reconstruction. The shower channel contributes about 23% of all signal events for an $E^{-2}$ energy spectrum. No significant excess over background is found. The most signal-like cluster of events is located at $(alpha,delta) = (343.8^circ, 23.5^circ)$ with a significance of $1.9sigma$. The neutrino flux sensitivity of the search is about $E^2 dvarPhi/dE = 6cdot10^{-9} GeV cm^{-2} s^{-1}$ for declinations from $-90^circ$ up to $-42^circ$, and below $10^{-8} GeV cm^{-2} s^{-1}$ for declinations up to $5^{circ}$. The directions of 106 source candidates and of 13 muon track events from the IceCube HESE sample are investigated for a possible neutrino signal and upper limits on the signal flux are determined.
The Earth is subjected to a uniform flux of very-high-energy (VHE, E > 100 GeV) cosmic rays unless they are obscured by an object, such as the Moon, in which case a deficit or shadow is created. Since cosmic rays are charged this deficit is deflected by the Earths magnetic field, enabling the rigidity of the obstructed cosmic rays to be determined. Measurement of the relative deficits of different species enables the positron fraction and the antiproton ratio to be measured. The April 15, 2014 lunar eclipse was visible with the VERITAS Cherenkov telescopes, which allowed (with special UV bandpass filters) 74 minutes of direct observations of the Moon and the associated deficit in the cosmic-ray flux. The results of this observation are presented. In addition VERITAS has been conducting a series of observations by pointing close to a partially illuminated Moon, with a reduced photomultiplier tube high voltage and UV bandpass filters. We present the technique developed for these observations and their current status.
We report on the observation of a significant deficit of cosmic rays from the direction of the Moon with the IceCube detector. The study of this Moon shadow is used to characterize the angular resolution and absolute pointing capabilities of the detector. The detection is based on data taken in two periods before the completion of the detector: between April 2008 and May 2009, when IceCube operated in a partial configuration with 40 detector strings deployed in the South Pole ice, and between May 2009 and May 2010 when the detector operated with 59 strings. Using two independent analysis methods, the Moon shadow has been observed to high significance (> 6 sigma) in both detector configurations. The observed location of the shadow center is within 0.2 degrees of its expected position when geomagnetic deflection effects are taken into account. This measurement validates the directional reconstruction capabilities of IceCube.