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TeV Diffuse Emission From the Inner Galaxy
Get PDFThe TeV diffuse emission from the Galactic plane is produced by multi TeV electrons and nuclei interacting with radiation fields and ambient gas, respectively. Measurements of the TeV diffuse emission help constrain CR origin and transport properties. We present a preliminary analysis of HAWC diffuse emission data from the inner Galaxy. The HAWC measurements will be used to constrain particle transport properties close to the Galaxy center correlating the HAWC maps with predictions of the DRAGON code
ANTARES time calibration
No full textNuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Volume 602, Issue 1, 11 April 2009, Pages 72-75
Proceedings of the 3rd International Workshop on a Very Large Volume Neutrino Telescope for the Mediterranean SeaThe ANTARES Collaboration has recently completed the construction of an underwater neutrino telescope located at 2475 km depth, 40 km away from the Toulon coast in France. The final detector consists of 885 photomultipliers (PMTs) distributed along 12 lines. At present, the deployed detector is the largest neutrino telescope in the northern hemisphere. The aim of ANTARES is the detection of cosmic neutrinos. A good angular resolution, which relies on a good time resolution and positioning, is required to identify the neutrino sources. In this contribution, we review the ANTARES time calibration systems, namely: (1) the on-shore dark room calibration, which allows the measurement of the relative time offsets among PMTs, (2) the echo-based clock system, which enables the measurement of the time delay of the signal from the clock board located on each storey to the shore station, (3) the internal LED, which monitors the PMTs transit time, (4) the Optical Beacons (OBs), which send light pulses that enable the relative time calibration of PMTs, and (5) the K40 calibration which together with the OBs allow a determination of time differences among PMTs of the same storey. These systems have shown that the required time resolution is achieved. Moreover, they ensure that the relative time offsets among PMTs are properly computed and, therefore, enable an optimized track reconstruction. The experience gained with ANTARES in the issue of time calibration is of great value in the design of the corresponding system for a VLVNT in the Mediterranean Sea.This work was supported by the Ministerio de Educación y Ciencia under the Grant BES-2004-5387
Recent results from the HAWC observatory
Get PDFThe High-Altitude Water Cherenkov Observatory (HAWC) is a TeV gamma-ray detector located at an altitude of 4100 meters on the slope of the Sierra Negra volcano in Puebla, Mexico. Inaugurated in March 2015, HAWC observes 65% of the sky every day with more than 90% duty cycle and an excellent angular resolution. HAWC plays an important role as a survey instrument for multi-wavelength studies, and presently is the most sensitive instrument to detect transients and extended sources of gamma-rays at multi-TeV energies. In this contribution I present the recent results from the experiment and discuss the future goals of the Collaboration
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
First Results from the HAWC Gamma-Ray Observatory
No full textAbstractThe High Altitude Water Cherenkov (HAWC) Observatory is a TeV gamma-ray detector located at an altitude of 4100 meters on the northern slope of the Sierra Negra volcano in the state of Puebla, Mexico. The detector will consist of 300 water Cherenkov detectors spread on a 22,000 square meter area, and is expected to be fully constructed by the end of 2014. Thanks to its large field-of-view, good angular resolution and >90% duty cycle, HAWC will allow us to study the Galactic sources at high energies (100 GeV – 100 TeV), diffuse gamma-ray emission, and transient emissions from active galactic nuclei and gamma-ray bursts. The detector started its continuous operation in August 2013 with a fraction of the array, and its size has been increasing since then. The first results of the experiment, with almost one year of data from the partial array, are reviewed in this proceedings
Variations on the Author
Get PDF“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
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