Orbital Compton-Getting Dipole with Cosmic Rays in IceCube

Every year, the Earth orbits the Sun at nearly 29.8 km/s, fast enough to leave a measurable imprint on the arrival directions and flux of cosmic rays — high-energy particles from space. Using data from the IceCube Neutrino Observatory at the South Pole, which records hundreds of millions of cosmic rays daily, we observe a solar dipole arising from the Compton–Getting effect. Earth’s motion through the cosmic-ray background produces an apparent excess of events in the direction of motion and a deficit in the opposite direction. The amplitude of this dipole depends on the orbital speed and the cosmic-ray spectral index, γ, which characterizes how the flux of cosmic rays decreases with increasing energy. We use twelve years of IceCube data to compare the time-dependent solar dipole signal to Compton-Getting predictions. The project will present the analysis of spectral index of cosmic-rays as a function of time and energy in the 10 TeV to 100 TeV range.