Analysis of Ice Cherenkov Detector Response Functions During a Latitude Survey

IceTop, IceCube Neutrino Observatory's surface component at the South Pole, detects cosmic ray air-showers using an array of ice Cherenkov detectors. Data from one such detector, housed in an insulated shipping container aboard the Swedish icebreaker Oden, was collected in November 2009 through a collaborative effort from the University of Delaware, University of Wisconsin-River Falls, and Uppsala University. Oden sailed from Helsingborg, Sweden to McMurdo Station, Antarctica, and returned in 2010. Traversing different geographic latitudes, the detector was effectively exposed to different geomagnetic cutoff rigidities. At any given Earth location, this cutoff translates to a minimum rigidity that a particle needs to travel from interplanetary space to the top of the Earth's atmosphere. During the latitude survey, solar modulation can cause variations in the cosmic ray particle flux measured at the Earth's surface, and our analysis will consider this event separately. From there, we obtain the response functions. These functions facilitate the computation of the energy-dependent effective area (or yield function) at sea level by using Earth as a magnetic spectrometer.