Large-scale sidereal anisotropy of multi-TeV galactic cosmic rays and the heliosphere
Abstract
We develop a model anisotropy best-fitting to the two-dimensional sky-map of multi-TeV galactic cosmic ray (GCR) intensity observed with the Tibet III air shower (AS) array. By incorporating a pair of intensity excesses in the hydrogen deflection plane (HDP) suggested by Gurnett et al., together with the uni-directional and bi-directional flows for reproducing the observed global feature, this model successfully reproduces the observed sky-map including the "skewed" feature of the excess intensity from the heliotail direction, whose physical origin has long remained unknown. These additional excesses are modeled by a pair of the northern and southern Gaussian distributions, each placed ~50 degree away from the heliotail direction. The amplitude of the southern excess is as large as ~0.2 %, more than twice the amplitude of the northern excess. This implies that the Tibet AS experiment discovered for the first time a clear evidence of the significant modulation of GCR intensity in the heliotail and the asymmetric heliosphere.
Keywords
Cite
@article{arxiv.0909.1026,
title = {Large-scale sidereal anisotropy of multi-TeV galactic cosmic rays and the heliosphere},
author = {M. Amenomori and X. J. Bi and D. Chen and S. W. Cui and Danzengluobu and L. K. Ding and X. H. Ding and C. Fan and C. F. Feng and Zhaoyang Feng and Z. Y. Feng and X. Y. Gao and Q. X. Geng and Q. B. Gou and H. W. Guo and H. H. He and M. He and K. Hibino and N. Hotta and Haibing Hu and H. B. Hu and J. Huang and Q. Huang and H. Y. Jia and L. Jiang and F. Kajino and K. Kasahara and Y. Katayose and C. Kato and K. Kawata and Labaciren and G. M. Le and A. F. Li and H. C. Li and J. Y. Li and C. Liu and Y. -Q. Lou and H. Lu and X. R. Meng and K. Mizutani and J. Mu and K. Munakata and A. Nagai and H. Nanjo and M. Nishizawa and M. Ohnishi and I. Ohta and S. Ozawa and T. Saito and T. Y. Saito and M. Sakata and T. K. Sako and M. Shibata and A. Shiomi and T. Shirai and H. Sugimoto and M. Takita and Y. H. Tan and N. Tateyama and S. Torii and H. Tsuchiya and S. Udo and B. Wang and H. Wang and Y. Wang and Y. G. Wang and H. R. Wu and L. Xue and Y. Yamamoto and C. T. Yan and X. C. Yang and S. Yasue and Z. H. Ye and G. C. Yu and A. F. Yuan and T. Yuda and H. M. Zhang and J. L. Zhang and N. J. Zhang and X. Y. Zhang and Y. Zhang and Yi Zhang and Ying Zhang and Zhaxisangzhu and X. X. Zhou and J. Kota},
journal= {arXiv preprint arXiv:0909.1026},
year = {2009}
}
Comments
4 pages, 1 figure, 31st International Cosmic Ray Conference (Lodz, Poland), 2009