Regresar

Cosmic Ray Anisotropy Over Time

Abstract:

IceCube is primarily a neutrino observatory, but it detects many more cosmic rays. Even before the detector was completed, a small anisotropy in cosmic ray arrival direction was found. This just means that cosmic rays are not arriving uniformly from every region of the sky. One way to parse out possible sources of this anisotropy is to look at data in different reference frames. These include the solar and sidereal frames, which can help us distinguish between effects due to Earth's motion around the Sun, and effects that are more distant and ambiguous. Anisotropy in solar time is expected to be a dipole due to a Compton-Getting effect, but we found a slightly better fit when we included an additional quadrupole component. This could hint at small underlying sources, like a possible effect due to atmospheric tides. Even frames that do not correspond to a physical meaning, like the anti-sidereal and extended-sidereal …