A Study of the Composition of Ultra–High‐Energy Cosmic Rays Using the High‐Resolution Fly’s Eye

Abbasi, Rasha; Abu‐Zayyad, T.; Archbold, G.; Atkins, R.; Bellido, J. A.; Belov, K.; Belz, J. W.; BenZvi, S.; Bergman, D. R.; Boyer, J.; Burt, G. W.; Cao, Zhen; Clay, R. W.; Connolly, B.; Dawson, B. R.; Deng, W.; Fedorova, Y.; Findlay, J.; Finley, C.; Hanlon, W.; Hughes, G.; Hüntemeyer, P.; Jui, C.; Kim, K.; Kirn, M.; Knapp, B.; Loh, E. C.; Maetas, M. M.; Martens, K.; Martin, G.; Manago, Naohiro; Mannel, E.; Matthews, John; Matthews, J. N.; O’Neill, A.; Perera, L.; Reil, K.; Riehle, R.; Roberts, M.; Sasaki, M.; Seman, M.; Schnetzer, S.; Simpson, K. M.; Smith, J. D.; Snow, R.; Sokolsky, P.; Song, C.; Springer, R. W.; Stokes, B. T.; Thomas, J. R.; Thomas, S. B.; Thomson, G. B.; Westerhoff, S.; Wiencke, L.; Zech, A.

doi:10.1086/427931

Cited by 198 publications

(161 citation statements)

References 27 publications

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“…show that this is sufficient to produce the observed gamma-ray emission and to accelerate nuclei within the jet to ultra-high energies ∼ > 10 19 eV per particle. GRBs associated with magnetar birth therefore provides a natural explanation for the otherwise puzzling observation by the Pierre Auger Observatory that the highest energies UHECRs are composed of heavy nuclei instead of protons (Abraham et al 2010, see however Abbasi et al 2005). This model is also consistent with constraints on the non-detection of high energy neutrinos coincident with GRBs with IceCube (Abbasi et al 2011), since nuclei typically lose energy through other processes than photo-pion production, and hence are not expected to be accompanied by a neutrino flux as large as that predicted for proton-dominated compositions.…”

Section: Gamma-ray Burst Engines and Uhecr Sourcesmentioning

confidence: 99%

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Vlasov

Metzger

Lippuner

et al. 2017

Monthly Notices of the Royal Astronomical Society

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We explore heavy element nucleosynthesis in neutrino-driven winds from rapidly-rotating, strongly magnetized proto-neutron stars ("millisecond proto-magnetars") for which the magnetic dipole is aligned with the rotation axis, and the field is assumed to be a static force-free configuration. We process the proto-magnetar wind trajectories calculated by Vlasov et al. (2014) through the r-process nuclear reaction network SkyNet using contemporary models for the evolution of the wind electron fraction during the proto-neutron star cooling phase. Although we do not find a successful second or third peak r-process for any rotation period P, we show that proto-magnetars with P ∼ 1 − 5 ms produce heavy element abundance distributions that extend to higher nuclear mass number than from otherwise equivalent spherical winds (with the mass fractions of some elements enhanced by factors of ∼ > 100 − 1000). The heaviest elements are synthesized by outflows emerging along flux tubes which graze the closed zone and pass near the equatorial plane outside the light cylinder. Due to dependence of the nucleosynthesis pattern on the magnetic field strength and rotation rate of the proto-neutron star, natural variations in these quantities between core collapse events could contribute to the observed diversity of the abundances of weak r-process nuclei in metal-poor stars. Further diversity, including possibly even a successful third-peak r-process, could be achieved for misaligned rotators with non-zero magnetic inclination with respect to the rotation axis. If proto-magnetars are central engines for GRBs, their relativistic jets should contain a high mass fraction of heavy nuclei of characteristic mass numberĀ ≈ 100, providing a possible source for ultra-high energy cosmic rays comprised of heavy nuclei with an energy spectrum that extends beyond the nominal GZK cut-off for protons or iron nuclei.

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Section: Gamma-ray Burst Engines and Uhecr Sourcesmentioning

confidence: 99%

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Vlasov

Metzger

Lippuner

et al. 2017

Monthly Notices of the Royal Astronomical Society

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“…The spread in the predictions for different hadronic interaction models is also shown. The experimental data are from the Fly's Eye [62], HiRes [73] and Yakutsk [74] experiments.…”

Section: Figmentioning

confidence: 99%

High energy neutrinos from astrophysical accelerators of cosmic ray nuclei

Anchordoqui

Hooper

Sarkar

et al. 2008

Astroparticle Physics

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Ongoing experimental efforts to detect cosmic sources of high energy neutrinos are guided by the expectation that astrophysical accelerators of cosmic ray protons would also generate neutrinos through interactions with ambient matter and/or photons. However there will be a reduction in the predicted neutrino flux if cosmic ray sources accelerate not only protons but also significant numbers of heavier nuclei, as is indicated by recent air shower data. We consider plausible extragalactic sources such as active galactic nuclei, gamma-ray bursts and starburst galaxies and demand consistency with the observed cosmic ray composition and energy spectrum at Earth after allowing for propagation through intergalactic radiation fields. This allows us to calculate the expected neutrino fluxes from the sources, normalized to the observed cosmic ray spectrum. We find that the likely signals are still within reach of next generation neutrino telescopes such as IceCube.PACS numbers: 95.85. Ry, 98.70.Rz, 98.54.Cm, 98.54.Ep

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“…Previous measurements of X max with the fluorescence technique have concentrated on the determination of the mean and standard deviation of the X max distribution [30][31][32][33]. Whereas with these two moments the overall features of primary cosmic-ray composition can be studied, and composition fractions in a three-component model can even be derived, only the distribution contains the full information on composition and hadronic interactions that can be obtained from measurements of X max .…”

Section: Introductionmentioning

confidence: 99%

Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above1017.8 eV

Aab¹,

Abreu²,

Aglietta³

et al. 2014

Phys. Rev. D

363

316

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We report a study of the distributions of the depth of maximum, Xmax, of extensive air-shower profiles with energies above 10 17.8 eV as observed with the fluorescence telescopes of the Pierre Auger Observatory. The analysis method for selecting a data sample with minimal sampling bias is described in detail as well as the experimental cross-checks and systematic uncertainties. Furthermore, we discuss the detector acceptance and the resolution of the Xmax measurement and provide parameterizations thereof as a function of energy. The energy dependence of the mean and standard 4 deviation of the Xmax-distributions are compared to air-shower simulations for different nuclear primaries and interpreted in terms of the mean and variance of the logarithmic mass distribution at the top of the atmosphere.

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A Study of the Composition of Ultra–High‐Energy Cosmic Rays Using the High‐Resolution Fly’s Eye

Cited by 198 publications

References 27 publications

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

Neutrino-heated winds from millisecond protomagnetars as sources of the weak r-process

High energy neutrinos from astrophysical accelerators of cosmic ray nuclei

Depth of maximum of air-shower profiles at the Pierre Auger Observatory. I. Measurements at energies above1017.8 eV

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