Abstract
It is shown that the expected dip in the diffuse photon spectrum above the threshold of e + e − pair production, i.e., at energies 1015–1017 eV, may be absent due to the synchrotron radiation by the electron component of the extragalactic ultrahigh-energy cosmic rays (UHE CRs) in the Galactic magnetic field. The mechanism we propose requires small (<2×10−12 G) extragalactic magnetic fields and a large photon fraction in the UHE CRs. For a typical photon flux expected in top-down scenarios of UHE CRs, the predicted flux in the region of the dip is close to the existing experimental limit. The sensitivity of our mechanism to the extragalactic magnetic field may be used to improve existing bounds on the latter by two orders of magnitude.
Similar content being viewed by others
References
R. J. Could and G. Schreder, Phys. Rev. Lett. 16, 252 (1966); J. P. Jelley, Phys. Rev. Lett. 16, 479 (1966).
K. Greisen, Phys. Rev. Lett. 16, 748 (1966); G. T. Zatsepin and V. A. Kuzmin, JETP Lett. 4, 78 (1966).
S. Lee, Phys. Rev. D 58, 043004 (1998).
P. Bhattacharjee and G. Sigl, “Origin and propagation of extremely high energy cosmic rays,” http://xxx.lanl.gov/abs/astro-ph/9811011.
S. I. Nikolsky, I. N. Stamenov, and S. Z. Ushev, J. Phys. G 13, 883 (1987).
A. V. Glushkov, L. G. Dedenko, N. N. Efimov et al., Proceedings of the 19th International Conference, La Jolla, edited by F. C. Jones, J. Adams, and G. M. Mason, National Technical Information Service, Springfield, Virginia (1985), Vol. 2, p. 186.
M. Aglietta, B. Alessandro, P. Antonioli et al., Astropart. Phys. 6, 71 (1996).
M. C. Chantel, C. E. Covault, J. W. Cronin et al., Phys. Rev. Lett. 79, 1805 (1997).
M. Takeda, N. Hayashida, K. Honda et al., Phys. Rev. Lett. 81, 1163 (1998); http://xxx.lanl.gov/abs/ astro-ph/9807193.
M. Teshima, Talk presented at 10th International School “Particles and Cosmology,” Baksan, 1999.
P. Blasi, “Gamma rays from superheavy relic particles in the halo,” http://xxx.lanl.gov/abs/astro-ph/9901390.
V. A. Kuzmin and V. A. Rubakov, Yad. Fiz. 61, 1122 (1988) [Phys. At. Nucl. 61, 1028 (1998); V. Berezinsky, M. Kachelriess, and A. Vilenkin, Phys. Rev. Lett. 79, 4302 (1997).
P. P. Kronberg, Rep. Prog. Phys. 47, 325 (1994).
L. D. Landau and E. M. Lifshits, The Classical Theory of Fields, 4th ed., Pergamon Press, Oxford (1975) [Russian original, 6th ed., Nauka, Moscow (1973)].
T. Stanev, Astrophys. J. 479, 290 (1997).
D. Ryu, H. Kang, and P. L. Biermann, Astron. Astrophys. 335, 19 (1998), http://xxx.lanl.gov/abs/astro-ph/9803275; T. A. Enβlin, P. L. Biermann, P. P. Kronberg, and X. P. Wu, Astrophys. J. 477, 560 (1997); http://xxx.lanl.gov/abs/astro-ph/9609190.
S. L. Dubovsky and P. G. Tinyakov, JETP Lett. 68, 107 (1998).
Author information
Authors and Affiliations
Additional information
Pis’ma Zh. Éksp. Teor. Fiz. 70, No. 8, 487–492 (25 October 1999)
Published in English in the original Russian journal. Edited by Steve Torstveit.
Rights and permissions
About this article
Cite this article
Dubovsky, S.L., Tinyakov, P.G. Generation of 1015–1017 eV photons by ultrahigh-energy cosmic rays in the Galactic magnetic field. Jetp Lett. 70, 495–501 (1999). https://doi.org/10.1134/1.568203
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1134/1.568203