Seyfert nuclei as sources of ultrahigh-energy cosmic rays

Uryson, A. V.

doi:10.1134/1.1648071

Cited by 10 publications

(22 citation statements)

References 48 publications

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“…The main models of cosmic ray acceleration in Seyfert Nuclei were proposed in [30][31][32] and LLAGNs, specially Seyfert galaxies nearby, were suggested as probable sources of UHECRs by [33][34][35]. Our present investigation endorses this idea, constraining that this occur mainly for massive Seyferts, comparing our results and upper limits to that obtained by the Fermi-LAT experiment.…”

Section: Introductionsupporting

confidence: 85%

Central accumulation of magnetic flux in massive Seyfert galaxies as a possible engine to trigger ultrahigh energy cosmic rays

Anjos

Coimbra-Araújo

2017

Phys. Rev. D

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In the present paper we investigate the production of ultra high energy cosmic rays (UHECRs) from Seyferts. We discuss the UHECR luminosities obtained by two possible engine trigger models: pure radiative transfer and the energy extraction from poloidal magnetic flux. The first case is modeled by Kerr slim disk or Bondi accretion mechanisms. Since it is assumed that the broadband spectra of Seyferts indicate that at least the outter portions of their accretion disks are cold and geometrically thin, and since our results point that the consequent radiative energy transfer is inefficient, we build the second approach based on massive Seyferts with sufficient central poloidal magnetic field to trigger an outflow of magnetically driven charged particles capable to explain the observed UHECRs and gamma-rays in Earth experiments from a given Seyfert source.

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Section: Introductionsupporting

confidence: 85%

Central accumulation of magnetic flux in massive Seyfert galaxies as a possible engine to trigger ultrahigh energy cosmic rays

Anjos

Coimbra-Araújo

2017

Phys. Rev. D

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“…Nevertheless the origin of ultrahigh-energy particles remains an open question. In this paper we present spectra and mass composition obtained within a model [16,17] in which nuclei of moderate-power Seyfert galaxies are put forward as UHECR sources. Comparison of calculation results with measurements allows us to reveal appropriate acceleration regimes and besides to define somehow distances to the most probable sources.…”

Section: Introductionmentioning

confidence: 99%

Spectra and mass composition of ultrahigh-energy cosmic rays from point sources

Калмыков

Shustova

Uryson

2012

J. Cosmol. Astropart. Phys.

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We present spectra and mass composition of cosmic rays incoming to the Earth in the energy range (0.5−2)·10 20 eV. As their sources we consider Seyfert galaxies located at distances 40 Mpc, following an acceleration model for such moderate-power objects. Mass composition of the particles at sources is assumed to be mixed. Generation spectra are described by a function E −γ0 , where γ 0 is an arbitrary parameter. It is shown that the assumptions adopted make it possible to describe experimental data provided by HiRes and Pierre Auger Observatory, using different values of γ 0 . a kalm@eas.sinp.msu.ru b olga.shustova@eas.sinp.msu.ru c uryson@sci.lebedev.ru arXiv:1112.5523v2 [astro-ph.HE]

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“…We estimated the CR luminosity of Seyfert nuclei previously [3,4]: (L CR ) S ≈10 40 erg s -1 for ? = 3 in the power-law initial CR spectrum and (L CR ) S ≈10 42 erg s -1 for ?…”

Section: 3estimates Of the Cr Luminosity For Sourcesmentioning

confidence: 99%

The maximum energy and spectra of cosmic rays accelerated in active galactic nuclei

Uryson

2004

Astron. Lett.

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Abstract. We computed the energy spectra of the incident (on an air shower array) ultrahighenergy (E > 4⋅10 19 eV) cosmic rays (CRs) that were accelerated in nearby Seyfert nuclei at redshifts z≤ 0.0092 and in BL Lac objects. These were identified as possible CR sources in our previous works. For our calculations, we took the distribution of these sources over the sky from catalogs of active galactic nuclei. In accordance with the possible particle acceleration mechanisms, the initial CR spectrum was assumed to be monoenergetic for BL Lac objects and a power law for Seyfert nuclei. The CR energy losses in intergalactic space were computed by the Monte Carlo method. We considered the losses through photopion reactions with background radiation and the adiabatic losses. The artificial proton statistic was 10 5 for each case considered.The maximum energy of the CRs incident on an external air shower (EAS) array was found to be 10 21 eV, irrespective of where they were accelerated. The computed spectra of the particles incident on an EAS array agree with the measurements, which indirectly confirms the adopted acceleration models. At energies E≥10 20 eV, the spectrum of the protons from nearby Seyfert nuclei that reached an EAS array closely matches the spectrum of the particles from BL Lac objects. BL Lac objects are, on average, several hundred Mpc away. Therefore, it is hard to tell whether a blackbody cutoff exists or not by analyzing the shape of the measured spectrum at E≥ 5⋅10 19 eV.

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Seyfert nuclei as sources of ultrahigh-energy cosmic rays

Cited by 10 publications

References 48 publications

Central accumulation of magnetic flux in massive Seyfert galaxies as a possible engine to trigger ultrahigh energy cosmic rays

Central accumulation of magnetic flux in massive Seyfert galaxies as a possible engine to trigger ultrahigh energy cosmic rays

Spectra and mass composition of ultrahigh-energy cosmic rays from point sources

The maximum energy and spectra of cosmic rays accelerated in active galactic nuclei

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