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Department of Physics

Staff profile

Publication details for Prof Sir Arnold Wolfendale

Erlykin, AD & Wolfendale, AW (2004). Cosmic rays and the Monogem supernova remnant. Astroparticle Physics 22(1): 47-63.
  • Publication type: Journal Article
  • ISSN/ISBN: 0927-6505
  • Keywords: HIGH-ENERGY; GAMMA-RAYS; INTERSTELLAR-MEDIUM; SINGLE-SOURCE; ORIGIN;RING; RADIATION; SPECTRUM; PULSARS; KNEE

Author(s) from Durham

Abstract

Recent findings indicate that the Monogem Ring and the associated
pulsar PSR B0656 + 14 may be the 'Single Source' responsible for the
formation of the sharp knee in the cosmic ray energy spectrum at
similar to3 PeV. The energy spectrum of cosmic rays expected for the
Monogem Ring supernova remnant (SNR) from our SNR acceleration model

J. Phys. G: Nucl. Part. Phys. 27 (2001) 9411 has been published by us
elsewhere [J. Phys. G: Nucl. Part. Phys. 29 (2003) 709

. In this paper
we go on to estimate the contribution of the pulsar B0656 + 14 to the
cosmic rays in the PeV region. We conclude that although the pulsar can
contribute to the formation of the knee, it cannot be the dominant
source of it and an SNR is still needed.
We also examine the possibility of the pulsar giving the peak of the
extensive air shower (EAS) intensity observed from the region inside
the Monogern Ring [Ap] Lett. 597 (2003) L129]. The estimates of the
gamma-ray flux produced by cosmic ray particles from this pulsar
indicate that it can be the source of the observed peak, if the
particles were confined within the SNR during a considerable fraction
of its total age. The flux of gamma quanta at PeV energies has a high
sensitivity to the duration of the confinement. The estimates of this
time and of the following diffusion of cosmic rays from the confinement
volume turn out to be in remarkable agreement with the time needed for
these cosmic rays to propagate to the solar system and to form the
observed knee in the cosmic ray energy spectrum.
Other possible mechanisms for the production of particles which could
give rise to the observed narrow peak in the EAS intensity were also
examined. Electrons scattered on the microwave background or on X-rays,
emitted by SNR, cannot be responsible for the gamma-quanta in the peak.
Neutrons produced in PP-collisions or released from the disintegration
of accelerated nuclei seem to be also unable to create the peak since
they cannot give the observed flux.
If the experimental EAS results concerning a point-like source are
confirmed, they can be important, since
(i) they will give evidence for the acceleration of protons or heavier
nuclei by the pulsar;
(ii) they will give evidence for the existence of a confinement
mechanism in SNR;
(iii) they will confirm that cosmic rays produced by the Monogem Ring
SNR and associated pulsar B0656 + 14 were released recently giving rise
to the formation of the sharp knee and the observed narrow peak in the
EAS intensity;
(iv) they will give strong support for the Monogem Ring SNR and the
associated pulsar B0656 + 14 being identified as the Single Source
proposed in our Single Source Model of the knee.
A number of predictions of the examined mechanism are made. (C) 2004
Elsevier B.V. All rights reserved.