Erratum: Energy spectra of gamma rays, electrons, and neutrinos produced at proton-proton interactions in the very high energy regime [Phys. Rev. D<b>74</b>, 034018 (2006)]

Kelner, S. R.; Aharonian, F.; Bugayov, V. V.

doi:10.1103/physrevd.79.039901

Cited by 462 publications

(780 citation statements)

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“…Neumann et al 2003) and resulted in E th ∼ 3.9 × 10 62 and 1.4 × 10 63 erg for regions within 0.2 and 0.4 degrees from the cluster centre respectively. The expected γ-ray emission has been computed following Kelner et al (2006) and assuming that the energy spectrum for CR protons is a single power law with spectral index α = 2.1 and 2.3 starting at an energy of 1 GeV. The assumption of such hard spectra is justified by the fact that, due to CR confinement within the intracluster medium, the equilibrium spectrum must be equal to the CR injection spectrum at the sources.…”

Section: Discussionmentioning

confidence: 99%

Constraints on the multi-TeV particle population in the Coma galaxy cluster with HESS observations

Aharonian

Akhperjanian

Anton

et al. 2009

A&A

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Aims. Galaxy clusters are key targets in the search for ultra high energy particle accelerators. The Coma cluster represents one of the best candidates for such a search owing to its high mass, proximity, and the established non-thermal radio emission centred on the cluster core. Methods. The HESS (High Energy Stereoscopic System) telescopes observed Coma for ∼8 h in a search for γ-ray emission at energies >1 TeV. The large 3.5 • FWHM field of view of HESS is ideal for viewing a range of targets at various sizes including the Coma cluster core, the radio-relic (1253+275) and merger/infall (NGC 4839) regions to the southwest, and features greater than 1 • away. Results. No evidence for point-like nor extended TeV γ-ray emission was found and upper limits to the TeV flux F(E) for E > 1, >5, and >10 TeV were set for the Coma core and other regions. Converting these limits to an energy flux E 2 F(E) the lowest or most constraining is the E > 5 TeV upper limit for the Coma core (0.2 • radius) at ∼8% Crab flux units or ∼10 −13 ph cm −2 s −1 . Conclusions. The upper limits for the Coma core were compared with a prediction for the γ-ray emission from proton-proton interactions, the level of which ultimately scales with the mass of the Coma cluster. A direct constraint using our most stringent limit for E > 5 TeV, on the total energy content in non-thermal protons with injection energy spectrum ∝E −2.1 and spatial distribution following the thermal gas in the cluster, is found to be ∼0.2 times the thermal energy, or ∼10 62 erg. The E > 5 TeV γ-ray threshold in this case corresponds to cosmic-ray proton energies > ∼ 50 TeV. Our upper limits rule out the most optimistic theoretical models for gamma ray emission from clusters and complement radio observations which constrain the cosmic ray content in clusters at significantly lower proton energies, subject to assumptions on the magnetic field strength.

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Section: Discussionmentioning

confidence: 99%

Constraints on the multi-TeV particle population in the Coma galaxy cluster with HESS observations

Aharonian

Akhperjanian

Anton

et al. 2009

A&A

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“…9 When upstream thermal particles cross the shock the first time and interact with the downstream plasma, they obtain a plasma frame momentum of ≃ 10 m p c. These spectra have an arbitrary absolute scale but are normalized to total proton number in each emitting region to isolate the effects from a varying p-dependence for λ mfp . The pion-decay emission is calculated using parameterizations given by Kamae et al (2006Kamae et al ( , 2007 and Kelner et al (2009). The dotted curve is the TP γ-ray emission for model J parameters assuming that 5% of the proton energy flux goes into Fermi accelerated CRs.…”

Section: Injection In Um Shocksmentioning

confidence: 99%

Particle spectra and efficiency in nonlinear relativistic shock acceleration – survey of scattering models

Ellison

Warren

Bykov

2015

Mon. Not. R. Astron. Soc.

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We include a general form for the scattering mean free path, λ mfp (p), in a nonlinear Monte Carlo model of relativistic shock formation and Fermi acceleration. Particle-in-cell (PIC) simulations, as well as analytic work, suggest that relativistic shocks tend to produce short-scale, self-generated magnetic turbulence that leads to a scattering mean free path with a stronger momentum dependence than the λ mfp ∝ p dependence for Bohm diffusion. In unmagnetized shocks, this turbulence is strong enough to dominate the background magnetic field so the shock can be treated as parallel regardless of the initial magnetic field orientation, making application to γ-ray bursts (GRBs), pulsar winds, Type Ibc supernovae, and extra-galactic radio sources more straightforward and realistic. In addition to changing the scale of the shock precursor, we show that, when nonlinear effects from efficient Fermi acceleration are taken into account, the momentum dependence of λ mfp (p) has an important influence on the efficiency of cosmic-ray production as well as the accelerated particle spectral shape. These effects are absent in non-relativistic shocks and do not appear in relativistic shock models unless nonlinear effects are self-consistently described. We show, for limited examples, how the changes in Fermi acceleration translate to changes in the intensity and spectral shape of γ-ray emission from proton-proton interactions and pion-decay radiation.

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“…It is taken as D b = K × 10 28 cm 2 s −1 , where K is a constant, and is kept as a parameter in the study which will be determined based on the observed gamma-ray emission profile. Since this study is mainly concerned with cosmic rays of kinetic energies above ∼ 1 GeV, the weak logarithmic energy dependence of σ at high energies [20] will be neglected, and a constant cross-section of σ = 32 mb will be considered in the study.…”

Section: Cosmic-ray Distributionmentioning

confidence: 99%

“…The values ofk andñ are taken as k = 0.17 andñ = 1 from Ref. [20], and a constant inelastic cross-section of σ = 32 mb will be assumed. The γ-ray intensity in a given direction is calculated as…”

Section: Gamma-ray Emission From the Bubblesmentioning

confidence: 99%

A possible origin of gamma rays from the Fermi Bubbles

Thoudam¹

2014

Nuclear Physics B - Proceedings Supplements

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One of the most exciting discoveries of recent years is a pair of gigantic gamma-ray emission regions, the socalled Fermi bubbles, above and below the Galactic center. The bubbles, discovered by the Fermi space telescope, extend up to ∼ 50 • in Galactic latitude and are ∼ 40 • wide in Galactic longitude. The gamma-ray emission is also found to correlate with radio, microwave and X-rays emission. The origin of the bubbles and the associated non-thermal emissions are still not clearly understood. Possible explanations for the non-thermal emission include cosmic-ray injection from the Galactic center by high speed Galactic winds/jets, acceleration by multiple shocks or plasma turbulence present inside the bubbles, and acceleration by strong shock waves associated with the expansion of the bubbles. In this paper, I will discuss the possibility that the gamma-ray emission is produced by the injection of Galactic cosmic-rays mainly protons during their diffusive propagation through the Galaxy. The protons interact with the bubble plasma producing π • -decay gamma rays, while at the same time, radio and microwave synchrotron emissions are produced by the secondary electrons/positrons resulting from the π ± decays.

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Erratum: Energy spectra of gamma rays, electrons, and neutrinos produced at proton-proton interactions in the very high energy regime [Phys. Rev. D74, 034018 (2006)]

Cited by 462 publications

References 0 publications

Constraints on the multi-TeV particle population in the Coma galaxy cluster with HESS observations

Constraints on the multi-TeV particle population in the Coma galaxy cluster with HESS observations

Particle spectra and efficiency in nonlinear relativistic shock acceleration – survey of scattering models

A possible origin of gamma rays from the Fermi Bubbles

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