Gaussian analysis of two hemisphere observations of galactic cosmic ray sidereal anisotropies

We have analyzed the yearly averaged sidereal daily variations in the count rates of 44 underground muon telescopes by fitting Gaussian functions to the data. These functions represent the Loss-cone (LC) and Tail-in (TI) anisotropies of the recent sidereal anisotropies model proposed by Nagashima et al. (1). The underground muon telescopes cover the median rigidity range 143 GV-1400 GV and almost entire celestial sphere. From the Gaussian amplitudes and positions we have confirmed that the TI anisotropy is more prominent in the southern hemisphere with its reference axis located at declination (δ)≈14 °S, and right ascension (α)≈4.7 sidereal hours. The TI anisotropy is asymmetric about its reference axis and the observed time of maximum intensity depends on the viewing latitude of the underground muon telescopes. We have used the parameters of the Gaussian fits to devise an empirical model of the sidereal anisotropies. We present these results and discuss the TI anisotropy in relation to the model heliosph...