1,721,028 research outputs found

    Search for GRB neutrino emission according to the photospheric model with the ANTARES telescope

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    The ANTARES detector is the largest neutrino telescope currently in operation in the North Hemisphere. One of the main goals of the ANTARES detector is the search for cosmic neutrino sources including transient sources like GRBs. In the so-called photospheric model for the emission from GRBs the interaction of the radiation field with the leptonic component of the outflow could lower the expected energy spectrum of the associated neutrino emission from GRBs. In coincidence with a GRB alert from a satellite, ANTARES stores a window of few minutes of unfiltered data. A dedicated directional filtering and reconstruction is applied offline to enhance the sensitivity in the lower energy range of the ANTARES detector (50 GeV - 10 TeV). The expected improvement as derived from Monte Carlo simulations will be presented

    Moon shadow observation with the ANTARES neutrino telescope

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    The ANTARES detector is the largest neutrino telescope currently in operation in the North Hemisphere. One of the main goals of the ANTARES telescope is the search for point-like neutrino sources. For this reason both the pointing accuracy and the angular resolution of the detector are important and a reliable way to evaluate these performances is needed. One possibility to measure the angular resolution and the pointing accuracy is to analyse the shadow of the Moon, i.e. the deficit in the atmospheric muon flux in the direction of the Moon induced by absorption of cosmic rays. Analysing the data taken between 2007 and 2012, the Moon shadow is detected with about 3s significance in the ANTARES data. The first measurement of the ANTARES angular resolution and absolute pointing for atmospheric muons using a celestial calibration source is obtained. The presented results confirm the good pointing performance of the detector as well as the predicted angular resolution

    Moon shadow observation with the ANTARES neutrino telescope

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    One of the main goals of the ANTARES telescope is the search for point-like neutrino sources. For this reason both the pointing accuracy and the angular resolution of the detector are important and a reliable way to evaluate these performances is needed. One possibility to measure the angular resolution and the pointing accuracy is to analyse the shadow of the Moon, i.e. the deficit in the atmospheric muon flux in the direction of the Moon induced by absorption of cosmic rays. Analysing the data taken between 2007 and 2012, the Moon shadow is detected with about 3.1σ significance in the ANTARES data

    Moon shadow observation with ANTARES and KM3NeT neutrino telescope

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    The ANTARES detector is the largest neutrino telescope currently in operation in the Northern Hemisphere. The search for point-like neutrino sources is one of the main goals of ANTARES, so a reliable way to evaluate the detector pointing performance is needed. The Moon shadow measurement, i.e. the deficit in the atmospheric muon flux in the direction of the Moon induced by absorption of cosmic rays, allows the estimation of the angular resolution and the pointing accuracy. The 2007–2012 ANTARES data set shows a significance of Moon shadowing around 3σ. This is the first measurement of the ANTARES angular resolution and absolute pointing for atmospheric muons using a celestial calibration source. The same approach has been used to estimate also the expected Moon shadow significance with the KM3NeT-ARCA detector, the future cubic kilometre scale detector that will be installed in Sicily

    ANTARES and KM3NeT: The Latest Results of the Neutrino Telescopes in the Mediterranean

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    The measurement of cosmic neutrinos is a new and unique method to observe the Universe. Neutrinos are chargeless, weakly-interacting particles that can provide information about the interior of an astrophysical object for cosmological distances. Indeed, they are a complementary probe with respect to other messengers such as multi-wavelength light and charged cosmic rays, allowing the observation of the far Universe and providing information on the production mechanism. Here, the neutrino telescopes in the Mediterranean Sea that are operating or in progress will be reviewed. The ANTARES (Astronomy with a Neutrino Telescope and Abyss environmental RESearch) detector is the largest neutrino telescope currently in operation in the Mediterranean Sea and the first operating in sea water. Some of the ANTARES results will be summarized, including diffuse, point-like, and multi-messenger source searches. Finally, the future km(3)-scale telescope KM3NeT (Cubic Kilometre Neutrino Telescope) will be described focusing on the expected performances and sensitivities

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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