EXTRACTING THE SIZE OF THE COSMIC ELECTRON-POSITRON ANOMALY
Katie Auchettl, Csaba Balazs
ASTROPHYSICAL JOURNAL | IOP PUBLISHING LTD | Published : 2012
We isolated the anomalous part of the cosmic electron-positron flux within a Bayesian likelihood analysis. Using 219 recent cosmic-ray spectral data points, we inferred the values of selected cosmic-ray propagation parameters. In the context of the propagation model coded in GalProp, we found a significant tension between the electron-positron related and the rest of the fluxes. Interpreting this tension as the presence of an anomalous component in the electron-positron related data, we calculated background predictions for PAMELA and Fermi-LAT based on the non-electron-positron related fluxes. We found a deviation between the data and the predicted background even when uncertainties, includ..View full abstract
Awarded by Australian Research Council
Awarded by Chinese Academy of Sciences
The authors are indebted to R. Cotta, A. Donea, J. Lazendic-Galloway, Y. Levin, A. Mazumdar, N. Sahu, and T. Porter for invaluable discussions on various aspects of cosmic-ray physics and likelihood analysis. K. A. is thankful to P. Chan for help with issues of parallel computing, to M. Jasperse for assistance in Mathematica programming, and to J. Lazendic-Galloway, T. Porter, and A. Vladimirov for help with GalProp. This research was funded in part by the Australian Research Council under Project ID DP0877916 and in part by the Project of Knowledge Innovation Program (PKIP) of Chinese Academy of Sciences, Grant No. KJCX2.YW.W10. The use of Monash University Sun Grid, a high-performance computing facility, is also gratefully acknowledged.