Repository of University of Nova Gorica

Search the repository
A+ | A- | Help | SLO | ENG

Query: search in
search in
search in
search in
* old and bolonia study programme

Options:
  Reset


1 - 6 / 6
First pagePrevious page1Next pageLast page
1.
Magnetic anisotropy of strontium ferrite nanoparticles
F. Albertini, C. Sangregorio, Blaž Belec, A. Quesada, T. Schliesch, M. Suara-Muzquiz, Petra Jenuš, M. Albino, M. Petrecca, M. Cabassi, D. Mishra, Cesar de Julian Fernandez, 2019, published scientific conference contribution abstract

Found in: ključnih besedah
Keywords: hexaferrite, nanoparticles, magnetic anisotropy, SPD
Published: 04.06.2019; Views: 551; Downloads: 0
.pdf Fulltext (36,89 MB)

2.
Search for Anisotropy in the Ultra High Energy Cosmic Ray Spectrum using the Telescope Array Surface Detector
J.P. Lundquist, R.U. Abbasi, 2017, other component parts

Abstract: The Telescope Array (TA) experiment is located in the western desert of Utah, USA, and observes ultra high energy cosmic rays (UHECRs) in the Northern hemisphere. At the highest energies, E>10~EeV, the shape of cosmic ray energy spectrum may carry an imprint of the source density distribution along the line of sight different in different directions of the sky. In this study, we search for such directional variations in the shape of the energy spectrum using events observed with the Telescope Array's surface detector. We divide the TA field of view into two nearly equal-exposure regions: the "on-source" region which we define as ±30∘ of the supergalactic plane containing mostly nearby structures, and the complementary "off-source" region where the sources are further away on average. We compare the UHECR spectra in these regions by fitting them to the broken power law and comparing the resulting parameters. We find that the off-source spectrum has an earlier break at highest energies. The chance probability to obtain such or larger difference in statistically equivalent distributions is estimated as 6.2±1.1×10−4 (3.2σ) by a Monte-Carlo simulation. The observed difference in spectra is in a reasonable quantitative agreement with a simplified model that assumes that the UHECR sources trace the galaxy distribution from the 2MRS catalogue, primary particles are protons and the magnetic deflections can be neglected.
Found in: ključnih besedah
Summary of found: ...catalogue, primary particles are protons and the magnetic deflections can be neglected....
Keywords: cosmic radiation: UHE, detector: surface, cosmic radiation: spectrum, cosmic radiation: energy spectrum, deflection: magnetic, numerical calculations: Monte Carlo, anisotropy
Published: 27.04.2020; Views: 78; Downloads: 4
.pdf Fulltext (169,05 KB)

3.
Supergalactic Structure of Multiplets with the Telescope Array Surface Detector
P. Sokolsky, J.P. Lundquist, 2019, published scientific conference contribution

Abstract: Evidence of supergalactic structure of multiplets has been found for ultra-high energy cosmic rays (UHECR) with energies above 10^19 eV using 7 years of data from the Telescope Array (TA) surface detector. The tested hypothesis is that UHECR sources, and intervening magnetic fields, may be correlated with the supergalactic plane, as it is a fit to the average matter density within the GZK horizon. This structure is measured by the average behavior of the strength of intermediate-scale correlations between event energy and position (multiplets). These multiplets are measured in wedge-like shapes on the spherical surface of the fieldof-view to account for uniform and random magnetic fields. The evident structure found is consistent with toy-model simulations of a supergalactic magnetic sheet and the previously published Hot/Coldspot results of TA. The post-trial probability of this feature appearing by chance, on an isotropic sky, is found by Monte Carlo simulation to be ~4.5σ.
Found in: ključnih besedah
Summary of found: ...hypothesis is that UHECR sources, and intervening magnetic fields, may be correlated with the supergalactic... ...UHECR, cosmic rays, energy spectrum, anisotropy, large-scale structure, magnetic deflection...
Keywords: UHECR, cosmic rays, energy spectrum, anisotropy, large-scale structure, magnetic deflection
Published: 28.04.2020; Views: 89; Downloads: 4
.pdf Fulltext (1,38 MB)

4.
Evidence of Intermediate-Scale Energy Spectrum Anisotropy in the Northern Hemisphere from Telescope Array
J.P. Lundquist, 2018, published scientific conference contribution

Abstract: Evidence of an energy dependent intermediate-scale anisotropy has been found in the arrival directions of ultra-high energy cosmic rays in the northern hemisphere, using 7 years of TA surface detector data. The previously reported ``hot spot" excess E ≥ 10^19.75 EeV is found to correspond to a deficit, or ``cold spot," of events for 10^19.2≤ E < 10^19.75 EeV. This feature suggests energy dependent magnetic deflection of cosmic-rays. The global post-trial significance of the energy spectrum deviation is found to be 3.74σ.
Found in: ključnih besedah
Summary of found: ...10^19.75 EeV. This feature suggests energy dependent magnetic deflection of cosmic-rays. The global post-trial significance...
Keywords: UHECR, cosmic rays, energy spectrum, anisotropy, magnetic deflection
Published: 28.04.2020; Views: 87; Downloads: 4
.pdf Fulltext (4,87 MB)

5.
Telescope Array Hot/Coldspot Study – Intermediate Scale Anisotropy
J.P. Lundquist, published scientific conference contribution abstract

Abstract: Indications of energy dependent intermediate scale anisotropy has been found in the arrival directions of ultra high energy cosmic rays with energies above 20 EeV in the northern hemisphere, using 7 years of TA surface detector data. The previously reported “hotspot‘” excess for E>57 EeV is found to correspond to a deficit, or “coldspot ”, of events for energies 2057 EeV has a Li Ma statistical significance of 4.62σ, and the deficit for energies 20Found in: ključnih besedah
Summary of found: ...The hot/ coldspot feature suggests energy dependent magnetic deflection of the isotropic background and cosmic rays...
Keywords: cosmic rays, energy spectrum, anisotropy, magnetic deflection
Published: 28.04.2020; Views: 90; Downloads: 0
.pdf Fulltext (2,25 MB)

6.
Energy-position correlation anisotropy of ultra-high energy cosmic rays with Telescope Array Data
J.P. Lundquist, published scientific conference contribution abstract

Abstract: Indication of an energy dependent intermediate-scale anisotropy has been found in the arrival directions of ultra-high energy cosmic rays with energies above 20 EeV in the northern hemisphere, using 7 years of TA surface detector data. The previously reported “hotspot“ excess for E>57 EeV is found to correspond to a deficit, or “coldspot“, of events for energies 2057 EeV has a Li-Ma statistical significance of 4.62σ, and the deficit for energies 20Found in: ključnih besedah
Summary of found: ...supergalactic plane. The hot/coldspot feature suggests energy dependent magnetic deflection of the isotropic background and cosmic-rays...
Keywords: UHECR, energy spectrum, anisotropy, magnetic deflection
Published: 29.04.2020; Views: 74; Downloads: 0
.pdf Fulltext (1,84 MB)

Search done in 0 sec.
Back to top