Microlensing candidate selection and detection efficiency for the SuperMACHO Dark Matter search

One of the outstanding questions in modern cosmology is understanding the composition of the Dark Matter within our own Galaxy. The 5.7 year MACHO project which was completed in 2000, provided a rather vexing answer to this question. The MACHO project sought to place constraints on the fraction of the Galactic Dark Matter composed of MAssive Compact Halo Objects (MACHOs), or sub-stellar mass objects in the Milky Way halo. To accomplish this goal, the MACHO team measured the rate of gravitational microlensing toward the Magellanic Clouds to infer the MACHO concentration along the line-of-sight. The project's finding was vexing in that while the largest Milky Way halo mass fraction consistent with the results was not sufficient to explain all the "missing" matter in the Galaxy, the rate of microlensing observed could not be explained by known populations of objects. The SuperMACHO project seeks to independently verify the optical depth toward the Large Magellanic Cloud and also provide additional clues regarding the location of the lens. By determining the differential rate of microlensing across the face of the LMC, SuperMACHO distinguishes between "screen-" and "self-" lensing scenarios. This thesis describes the selection criteria used to arrive at a candidate set of microlensing events from the SuperMACHO survey and the efficiency with which the SuperMACHO project detects microlensing. The efficiency analysis is accomplished by simulating light curves over a spatial and temporal subset of the survey data. Assuming the optical depth observed by the MACHO project, we expect 14 microlensing events to pass our tighter set of selection criteria in this subset of data. Because type Ia supernovae remain a persistent contaminant in the SuperMACHO candidate set, this thesis also describes a method for determining the expected number of supernova contaminants in the SuperMACHO candidate set. We expect between 6 and 12 type Ia supernovae depending on which supernova rate we assume (10--4.5 yr--1 Mpc--3 or 10--4.2 yr--1 Mpc--3). Overall, we find 24 microlensing candidate events passing our tighter set of selection criteria, and 20 of these fall into the subset of data included in the efficiency analysis.