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A new method to search for a cosmic ray dipole anisotropy

Silvia Mollerach·Esteban Roulet
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Abstract

We propose a new method to determine the dipole (and quadrupole) component of a distribution of cosmic ray arrival directions, which can be applied when there is partial sky coverage and/or inhomogeneous exposure. In its simplest version it requires that the exposure only depends on the declination, but it can be easily extended to the case of a small amplitude modulation in right ascension. The method essentially combines a $χ^2$ minimization of the distribution in declination to obtain the multipolar components along the North-South axis and a harmonic Rayleigh analysis for the components involving the right ascension direction.

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Silvia Mollerach, Esteban Roulet. 2005-04-28. A new method to search for a cosmic ray dipole anisotropy. https://doi.org/10.1088/1475-7516%2F2005%2F08%2F004

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