Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 11 of 11 for “"Gamma-ray astronomy"”.
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Gamma ray astronomy in the low energy range
A low energy gamma ray telescope, and the results of its observations are described. The telescope consisted of four sodium iodide crystals, each of 120 cm<sup>2</sup> area, occulted by lead discs. Charged particles are rejected using scintillation, anti-coincidence shields.<br/><br/>The telescope …
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Observations of variability of TeV gamma-ray blazars
The boom in ground-based gamma-ray astronomy since the beginning of the 21st century has enabled a new probe of the universe using very-high-energy photons. The Very Energetic Radiation Imaging Telescope Array System (VERITAS) is an array of four 12-m imaging Cherenkov telescopes that is sensitive …
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Towards Gamma-Ray Telescopes in Australia
Recent decades have seen the rise of the field of gamma-ray astronomy, probing the most extreme environments in our Universe. The upcoming Cherenkov Telescope Array Observatory (CTAO), alongside H.E.S.S. in Namibia, are Imaging Air Cherenkov Telescopes (IACTs) that will cover roughly two thirds of …
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Collecting heat during the day, observing the sky at night : the use of a heliostat field near Almeria to search for cosmic gamma rays
The GRAAL experiment (Gamma Ray Astronomy at ALmeria) is the result of the conversion of a solar power plant near Almeria into a Cherenkov telescope with a total mirror area of 2500 m^2 for very high energy gamma astronomy. The detector is located in a central solar tower and detects photon-induced …
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Very High Energy Gamma-Rays from Binary Systems
… presents a study of the very high energy (VHE) gamma-ray emission from X-ray binary systems using the H.E.S.S. imaging atmospheric Cherenkov array. The historical background and basic principles of ground-based gamma-ray astronomy are briefly reviewed and an overview of the design and …
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Crab flare observations with H.E.S.S. phase II
The H.E.S.S. array is a third generation Imaging Atmospheric Cherenkov Telescope (IACT) array. It is located in the Khomas Highland in Namibia, and measures very high energy (VHE) gamma-rays. In Phase I, the array started data taking in 2004 with its four identical 13 m telescopes. Since then, …
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Search for gamma-ray emission from bow shocks of runaway stars
The mystery of the origin of cosmic rays has been tackled for more than hundred years and is still not solved. Cosmic rays are detected with energies spanning more than 10 orders of magnitude and reaching energies up to ~10²¹ eV, far higher than any man-made accelerator can reach. Different …
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Photon reconstruction for the H.E.S.S. 28 m telescope and analysis of Crab Nebula and galactic centre observations
… reconstruction technique of ground-based γ-ray astronomy is adapted to the H.E.S.S. 28 m telescope. The method is based on a semi-analytical model of electromagnetic particle showers in the atmosphere. The properties of cosmic γ-rays are reconstructed by comparing the camera image of the …
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Pulsar wind nebulae at high energies
… wind nebulae (PWNe) are the most abundant TeV gamma-ray emitters in the Milky Way. The radiative emission of these objects is powered by fast-rotating pulsars, which donate parts of their rotational energy into winds of relativistic particles. This thesis presents an in-depth study of the …
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Stacking the Gamma-ray Sky to Search for Faint Astrophysical Populations
<p>Gamma-ray emission can be generated from a wide variety of high-energy astrophysical phenomena, from stellar flares to pulsating neutron stars, and from interstellar clouds to the center of the Milky Way Galaxy. Entering the 13th year of its orbit around Earth, the Fermi Space Gamma-ray …
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The search for dark matter annihilation in galaxy clusters at VERITAS
… into a variety of lighter particles including γ-rays. Many direct detection, indirect detection, and direct production schemes have been proposed to search for the elusive WIMP. Galaxy clusters, consisting of hundreds to thousands of galaxies, are the largest collections of matter in the Universe …