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41.
Astroparticles at the High Energy Frontier: Results from the Pierre Auger Observatory
Marko Zavrtanik, Danilo Zavrtanik, Serguei Vorobiov, Darko Veberič, Samo Stanič, Ahmed Saleh, Andrej Filipčič, Gonzalo Parente, 2014, objavljeni znanstveni prispevek na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...Pierre Auger Observatory, ultra-high energy cosmic rays (UHECR), UHECR energy spectrum, mass composition, anisotropies...
Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays (UHECR), UHECR energy spectrum, mass composition, anisotropies
Objavljeno: 20.06.2017; Ogledov: 1865; Prenosov: 0
.pdf Polno besedilo (1,06 MB)

42.
43.
Results from the Pierre Auger Observatory
Marko Zavrtanik, Danilo Zavrtanik, Darko Veberič, Samo Stanič, Andrej Filipčič, Ivan De Mitri, 2015, objavljeni znanstveni prispevek na konferenci

Najdeno v: ključnih besedah
Povzetek najdenega: ...Pierre Auger Observatory, Ultra High Energy Cosmic Rays (UHECR), UHECR energy spectrum, UHECR mass composition...
Ključne besede: Pierre Auger Observatory, Ultra High Energy Cosmic Rays (UHECR), UHECR energy spectrum, UHECR mass composition
Objavljeno: 27.06.2017; Ogledov: 1648; Prenosov: 0
.pdf Polno besedilo (475,69 KB)

44.
The Fermi Galactic Center GeV Excess and Implications for Dark Matter
Gabrijela Zaharijas, 2017, izvirni znanstveni članek

Najdeno v: ključnih besedah
Povzetek najdenega: ... cosmic rays – Galaxy: bulge – Galaxy: center...
Ključne besede: cosmic rays – Galaxy: bulge – Galaxy: center – Galaxy: halo – gamma rays: general – ISM: general
Objavljeno: 13.07.2017; Ogledov: 1641; Prenosov: 0
.pdf Polno besedilo (7,21 MB)

45.
Search for Physics beyond the Standard Model with the CRESST Experiment
2017, magistrsko delo

Opis: In spite of the successes of observational astro- and particle physics and cosmology very much of the universe remains unknown. The Standard Model of particle physics is a theory describing the electromagnetic, weak, and strong nuclear interactions, as well as classifying all the subatomic particles known. But there is overwhelming evidence, that all the known particles, the ordinary (baryonic) matter, the building blocks of planets, stars and ourselves, only make up about 4.9% of the energy content of the universe. The standard model of cosmology (CDM) indicates that the total mass-energy of the universe contains beside the 4.9% ordinary matter two other components: 26.8% dark matter and 68.3% dark energy. The accelerating expansion of the Universe is the result of the effect of the dark energy with its most simple form given by a cosmological constant in Einstein's Equation. Dark matter is an unidentified type of matter that is not accounted for by dark energy and neutrinos and is generally believed to be a non-relativistic, charge neutral and non-baryonic new form of matter. Although dark matter has not been directly observed yet, its existence and properties are inferred from its gravitational effects such as the motions of visible matter, gravitational lensing, its influence on the universe's large-scale structure, and its effects in the cosmic microwave background. Thus the search for Dark Matter is the search for physics beyond the standard model. Although the nature of dark matter is yet unknown, its presence is crucial to understanding the future of the universe. The CRESST experiment is searching for direct evidence in the form of a nuclear recoil induced on a scintillating CaWO4 crystal by a dark matter particle, and is installed and taking data underground at Laboratory Nazionali del Gran Sasso (LNGS) in Italy. While both, dark energy and dark matter, have not been detected directly, a class of dark matter particles that interact only via gravity and the weak force, referred to asWeakly Interacting Massive Particles (WIMPs), has been established as the leading candidate among the dark matter community. For this thesis a special model of dark matter was studied, namely the dark photon. This thesis provides a detailed description of the calculation of the 90% upper limit on the dark photon kinetic mixing based on data from the second phase of the CRESST experiment. The analysis was carried out in a frequentist approach based on the (unbinned) maximum-likelihood method and likelihood ratios. To make a statement about the calculated result and its quality, the used algorithm had to be tested, what was done with Monte Carlo simulations (pseudo data).
Najdeno v: ključnih besedah
Povzetek najdenega: ...large-scale structure, and its effects in the cosmic microwave background. Thus the search for Dark...
Ključne besede: astro physics, particle physics, cosmology, universe, Standard Model of particle physics, standard model of cosmology, matter, ordinary matter, dark matter, dark energy, accelerating expansion of the Universe, non-baryonic, new form of matter, gravitational lensing, cosmic microwave background, search for physics beyond the standard model, CRESST experiment, direct detection, CaWO4 crystal, underground laboratory, Laboratory Nazionali del Gran Sasso, Weakly Interacting Massive Particles, WIMP, dark photon, 90% upper limit, upper limit, kinetic mixing, frequentist approach, unbinned, maximum likelihood
Objavljeno: 13.10.2017; Ogledov: 1653; Prenosov: 0
.pdf Polno besedilo (10,71 MB)

46.
Astroparticle studies at the Pierre Auger Observatory
Lili Yang, predavanje na tuji univerzi

Opis: The Pierre Auger Observatory (PAO), the world’s largest cosmic ray detector combines a large surface detector (SD) with an air fluorescence detector (FD). It is designed to observe extensive air showers (EAS) of billions of secondary particles induced by the UHECRs in the earths’ atmosphere. The “hybrid” design (i.e., detected simultaneously by SD and FD) provides wealth of information about shower development and excellent event reconstruction. Together with observations of UHECRs, the Surface Detector (SD) of the PAO is sensitive to UHE neutrinos through the observation of deeply initiated inclined down-going showers produced by neutrino interactions in the atmosphere, which method has been well established. On the other hand, high-energy photons can also be discriminated from background of charged cosmic rays based on their characters of the shower front. In this talk, I will give a review on recent results from PAO and introduce the ultra-high energy multi-messenger studies from PAO.
Najdeno v: ključnih besedah
Povzetek najdenega: ...Pierre Auger Observatory (PAO), the world’s largest cosmic ray detector combines a large surface detector...
Ključne besede: Pierre Auger Observatory, cosmic rays, ultra-high energy
Objavljeno: 17.01.2018; Ogledov: 1173; Prenosov: 0
.pdf Polno besedilo (8,86 MB)
Gradivo ima več datotek! Več...

47.
Very high-energy gamma-ray signature of ultrahigh-energy cosmic-ray acceleration in Centaurus A
Jagdish Joshi, Marlui Miranda, Lili Yang, Soebur Razzaque, 2017, objavljeni povzetek znanstvenega prispevka na konferenci

Opis: The association of at least a dozen ultrahigh-energy cosmic-ray (UHECR) events with energy 54 EeV or higher detected by the Pierre Auger Observatory from the direction of Centaurus-A, the nearest radio galaxy, supports the scenario of UHECR acceleration in the jets of radio galaxies. Multiwavelength observations of Centaurus-A suggest that the inner jet is likely the site for particle acceleration, which emits in X-ray to very high-energy (VHE) gamma-ray. We model broadband spectral energy distribution with emission from shock-accelerated electrons and protons in a combined synchrotron-self-Compton and photo-hadronic scenario. The UHECR flux from Centaurus-A, required to explain Pierre Auger data, successfully explains observed VHE gamma rays as photo-hadronic emission.
Najdeno v: ključnih besedah
Ključne besede: Centaurus A, gamma ray, cosmic rays
Objavljeno: 17.01.2018; Ogledov: 1153; Prenosov: 0
.pdf Polno besedilo (2,27 MB)

48.
Analysis and characterization of thermal systematic effects on the PLANCK LFI data
Tanja Petrushevska, 2010, magistrsko delo

Opis: The cosmic microwave background radiation discovered by Penzias and Wilson in 1965, is considered one of the most important experimental evidences in favour of the Hot Big Bang standard cosmological model. This radiation provides an image of the Universe when it was about 380,000 years old and has a blackbody spectral distribution at temperature T=2.725±0.002 K, index of thermodynamic equilibrium with the mater in epoch when it was released. The cosmic background radiation presents anisotropies at level of 10 5 which provide valuable information about the origin and the evolution of the Universe. After the discovery of background radiation, tens of experiments have been performed to measure this radiation and its anisotropies. In 1992 the COBE satellite revolutionized cosmology by detecting temperature anisotropies for the first time. Launched on May 14, 2009, Planck is a European Space Agency mission designed to measure the CMB anisotropies with an accuracy set by fundamental astrophysical limits. To do this, Planck is imaging the whole sky with an unprecedented combination of sensitivity ( ΔT/T~2*10^-6), angular resolution (to 5’), and 9 frequency coverage (30 857 GHz). To reach these ambitious requirements, Planck uses an active cryogenic thermal system which cools the instruments to 0.1 K. The high sensitivity of the instrument and the cryogenic system makes the thermal systematic effects study of crucial importance to the scientific success. The thesis is divided into six chapters: 1. Chapter 1 explains the properties of the cosmic background radiation and its anisotropies; 2. Chapter 2 presents a short overview of the various experiments dedicated to the study of cosmic background radiation; 3. Chapter 3 describes the Planck mission, its instruments and its goals, in particular the Low Frequency Instrument (LFI) and its thermal structure; Chapter 4 discusses the analysis of the LFI thermal stability. This work was carried out in the Physics department at the University of Trieste, at the LFI Data Processing Centre located at INAF (Instituto Nazionale di AstroFisica) - OATS (Astronomical Observatory of Trieste); Chapter 5 presents the results of this analysis; in Chapter 6 conclusions are drawn and proposals for future work are discussed.
Najdeno v: ključnih besedah
Povzetek najdenega: ...The cosmic microwave background radiation discovered by Penzias and...
Ključne besede: Cosmic background radiation, CMB, Planck, satellite mission
Objavljeno: 24.01.2018; Ogledov: 992; Prenosov: 42
.pdf Polno besedilo (23,33 MB)

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50.
Cosmic-ray electron-positron spectrum from 7 GeV to 2 TeV with the Fermi Large Area Telescope
Gabrijela Zaharijas, 2017, izvirni znanstveni članek

Najdeno v: ključnih besedah
Ključne besede: Fermi LAT, Cosmic rays
Objavljeno: 15.02.2018; Ogledov: 1093; Prenosov: 0
.pdf Polno besedilo (1,07 MB)

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