The Milky Way as a Kiloparsec-Scale Axionscope [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 2007.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 7 pages : digital, PDF file
- Additional Creators:
- Fermi National Accelerator Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- Very high energy gamma-rays are expected to be absorbed by the extragalactic background light over cosmological distances via the process of electron-positron pair production. Recent observations of cosmologically distant gamma-ray emitters by ground based gamma-ray telescopes have, however, revealed a surprising degree of transparency of the universe to very high energy photons. One possible mechanism to explain this observation is the oscillation between photons and axion-like-particles (ALPs). Here we explore this possibility further, focusing on photon-ALP conversion in the magnetic fields in and around gamma-ray sources and in the magnetic field of the Milky Way, where some fraction of the ALP flux is converted back into photons. We show that this mechanism can be efficient in allowed regions of the ALP parameter space, as well as in typical configurations of the Galactic Magnetic Field. As case examples, we consider the spectrum observed from two HESS sources: 1ES1101-232 at redshift z = 0.186 and H 2356-309 at z = 0.165. We also discuss features of this scenario which could be used to distinguish it from standard or other exotic models.
- Report Numbers:
- E 1.99:fermilab-pub-07-658-a
- Other Subject(s):
- Published through SciTech Connect.
"arXiv eprint number arXiv:0712.2825"
Phys.Rev.D77:063001,2008 77 ISSN 1550-7998 FT
Serpico, Pasquale D.; Hooper, Dan; Simet, Melanie.
- Funding Information:
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