1,721,180 research outputs found
Measurement of the muon production depths at the Pierre Auger Observatory
No full textThe muon content of extensive air showers is an observable sensitive to the primary composition and to the hadronic interaction properties. The Pierre Auger Observatory uses water-Cherenkov detectors to measure particle densities at the ground and therefore is sensitive to the muon content of air showers. We present here a method which allows us to estimate the muon production depths by exploiting the measurement of the muon arrival times at the ground recorded with the Surface Detector of the Pierre Auger Observatory. The analysis is performed in a large range of zenith angles, thanks to the capability of estimating and subtracting the electromagnetic component, and for energies between 10(19.2) and 10(20)eV
“A scuola di Astroparticelle”: a synergy between school education and scientific research
No full textThe outreach program “A scuola di Astroparticelle” was proposed in 2016 by the National Institute for Nuclear Physics (INFN – Napoli Division) in collaboration with the Physics Department “Ettore Pancini” of the Federico II University in Napoli, CNR-SPIN and CNR-ISASI Institutes. Its main goal is to engage teachers and students of High Schools in astroparticle physics projects.
For the third edition (2018/19), the activities, which are also part of the Italian Educational Program PCTO – “Percorsi per le Competenze Trasversali e per l'Orientamento”, involved 18 schools for a total of 21 projects on several topics. Some projects were strictly related to astroparticles as cosmic rays, while others were more technical, as the development of particle detectors, or cross-disciplinary projects. Students worked for the entire school year and prepared for the final event. More than 600 students attended the event and presented their work to a jury with a poster and an oral presentation in plenary sessions.
Since 2018, the program is part of OCRA - Outreach Cosmic Ray Activities - a national outreach project of INFN with the aim of collecting, within a common framework, the numerous outreach activities in cosmic-ray field carried out at the local level.
The fourth edition (2019-20), in spite of the difficult situation due to the COVID-19 pandemic, has also seen the participation of 22 schools that carried out part of the activities in an online format.
Some projects will be presented in detail as the one performed using the open data of the Pierre Auger Observatory
Elves, Forbush Decreases and Solar Activity Studies at the Pierre Auger Observatory
No full textThe Pierre Auger Observatory, designed to observe cosmic rays at the highest energies, can also be
a valid ground based instrument for the observation of transient luminous events and for studying
the modulation of galactic cosmic rays due to solar activity. The Fluorescence Detector can observe
elves, transient luminous emissions from altitudes between 80 km and 95 km above sea level, with
timescales of tens of microseconds, which are triggered by lightning activity. A dedicated trigger
and an extended readout scheme were introduced to enhance detection efficiency of these events and
to improve the knowledge of some peculiar characteristics. The low energy mode of the Surface
Detector, on the other hand, records variations in the flux of low energy secondary particles with
extreme detail.With the Scaler mode, it is possible to register the rate of signals for deposited energies
between 15 MeV - 100 MeV; the Histogram mode, using the calibration peak and charge histograms
of the individual pulses detected by each water-Cherenkov station, covers different deposited energy
ranges up to 1 GeV. The variations in the flux of galactic cosmic rays have been studied on short
and intermediate time scales (Forbush decreases), but also a long-term analysis, which shows the
sensitivity of the Observatory to the solar cycle variation, is in progress
Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger Observatory with zenith angles up to 80 degrees
No full textWe present the results of an analysis of the large angular scale distribution of the arrival directions of cosmic rays with energy above 4 EeV detected at the Pierre Auger Observatory including for the first time events with zenith angle between 60° and 80°. We perform two Rayleigh analyses, one in the right ascension and one in the azimuth angle distributions, that are sensitive to modulations in right ascension and declination, respectively. The largest departure from isotropy appears in the EeV energy bin, with an amplitude for the first harmonic in right ascension , that has a chance probability , reinforcing the hint previously reported with vertical events alone
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Muons in air showers at the Pierre Auger Observatory: mean number in highly inclined events
No full textWe present the first hybrid measurement of the average muon number in air showers at ultrahigh energies, initiated by cosmic rays with zenith angles between 62° and 80°. The measurement is based on 174 hybrid events recorded simultaneously with the surface detector array and the fluorescence detector of the Pierre Auger Observatory. The muon number for each shower is derived by scaling a simulated reference profile of the lateral muon density distribution at the ground until it fits the data. A 1019??????eV shower with a zenith angle of 67°, which arrives at the surface detector array at an altitude of 1450 m above sea level, contains on average (2.68±0.04±0.48(sys))×107 muons with energies larger than 0.3 GeV. The logarithmic gain dlnN??/dlnE of muons with increasing energy between 4×1018??????eV and 5×1019??????eV is measured to be (1.029±0.024±0.030(sys))
Variations on the Author
Full text link“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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