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21.
Telescope Array Hot/Coldspot Study – Intermediate Scale Anisotropy
Jon Paul 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 20Keywords: cosmic rays, energy spectrum, anisotropy, magnetic deflection
Published in RUNG: 28.04.2020; Views: 2664; Downloads: 0
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22.
Supergalactic Structure of Multiplets with the Telescope Array Surface Detector
Jon Paul Lundquist, P. Sokolsky, 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.
Keywords: UHECR, cosmic rays, energy spectrum, anisotropy, large-scale structure, magnetic deflection
Published in RUNG: 28.04.2020; Views: 2735; Downloads: 149
.pdf Full text (1,38 MB)

23.
Supergalactic Structure of Energy-Angle Correlations
Jon Paul Lundquist, P. Sokolsky, 2020, published scientific conference contribution

Abstract: Evidence for the supergalactic structure of multiplets (energy-angle correlations) has previously been shown using ultra-high energy cosmic ray (UHECR) data from Telescope Array (TA) with energies above 10^19 eV. The supergalactic deflection hypothesis (that UHECR sources and intervening magnetic fields are correlated) is measured by the all-sky behavior of the strength of intermediate-scale correlations. The multiplets are measured in spherical surface wedge bins of the field-of-view to account for uniform and random magnetic fields. The structure found is consistent with the previously published energy spectrum anisotropy results of TA and toy-model simulations of a supergalactic magnetic sheet. The 7 year data post-trial significance of this feature appearing by chance, on an isotropic sky, was found by Monte Carlo simulation to be ∼4σ. The analysis has now been applied to 10 years of data.
Keywords: Cosmic rays, UHECR, energy spectrum, magnetic deflection, large-scale structure, supergalactic, multiplets
Published in RUNG: 27.04.2020; Views: 2613; Downloads: 85
.pdf Full text (1,66 MB)

24.
Search for Anisotropy in the Ultra High Energy Cosmic Ray Spectrum using the Telescope Array Surface Detector
R.U. Abbasi, Jon Paul Lundquist, 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.
Keywords: cosmic radiation: UHE, detector: surface, cosmic radiation: spectrum, cosmic radiation: energy spectrum, deflection: magnetic, numerical calculations: Monte Carlo, anisotropy
Published in RUNG: 27.04.2020; Views: 2744; Downloads: 98
.pdf Full text (169,05 KB)

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

Keywords: hexaferrite, nanoparticles, magnetic anisotropy, SPD
Published in RUNG: 04.06.2019; Views: 3467; Downloads: 0
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Synthesis of inorganic anisotropic nanoparticles
Blaž Belec, invited lecture at foreign university

Keywords: Magnetic nanoparticles, anisotropic nanoparticles, exchange coupled nanoparticles
Published in RUNG: 10.04.2019; Views: 3261; Downloads: 0
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30.
Combining hard and soft magnetic phases by mechanical mixing
Blaž Belec, Cesar De Jilian Fernandez, Daniela Bertoni, other performed works

Keywords: Magnetic materials Magnetodipolar interactions lorenz microscopy
Published in RUNG: 12.02.2019; Views: 3335; Downloads: 0
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