Astronomy and Astrophysics – Astrophysics – Instrumentation and Methods for Astrophysics
Scientific paper
2009-05-27
J.Phys.G36:115203,2009
Astronomy and Astrophysics
Astrophysics
Instrumentation and Methods for Astrophysics
Fixed PDF error
Scientific paper
10.1088/0954-3899/36/11/115203
The two-point angular correlation function is a traditional method used to search for deviations from expectations of isotropy. In this paper we develop and explore a statistically descriptive three-point method with the intended application being the search for deviations from isotropy in the highest energy cosmic rays. We compare the sensitivity of a two-point method and a "shape-strength" method for a variety of Monte-Carlo simulated anisotropic signals. Studies are done with anisotropic source signals diluted by an isotropic background. Type I and II errors for rejecting the hypothesis of isotropic cosmic ray arrival directions are evaluated for four different event sample sizes: 27, 40, 60 and 80 events, consistent with near term data expectations from the Pierre Auger Observatory. In all cases the ability to reject the isotropic hypothesis improves with event size and with the fraction of anisotropic signal. While ~40 event data sets should be sufficient for reliable identification of anisotropy in cases of rather extreme (highly anisotropic) data, much larger data sets are suggested for reliable identification of more subtle anisotropies. The shape-strength method consistently performs better than the two point method and can be easily adapted to an arbitrary experimental exposure on the celestial sphere.
Becker B. R.
Gold M. S.
Hague J. D.
Matthews John A. J.
No associations
LandOfFree
A Three-Point Cosmic Ray Anisotropy Method does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Three-Point Cosmic Ray Anisotropy Method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Three-Point Cosmic Ray Anisotropy Method will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-528444