Search m ethod for coincident events from LIG O and IceC ube detectors

A bstract. W e present a coincidence search m ethod for astronom ical events using gravitational wave detectors in conjunction with other astronom ical observations. W e illustrate our m ethod for the specic case of the LIG O gravitationalwave detector and the IceCube neutrino detector. LIG O trigger- events and IceCube events which occur within a given tim e window are selected as tim e-coincident events. Then the spatialoverlap ofthe reconstructed event directions is evaluated using an unbinned m axim um likelihood m ethod. O ur m ethod was tested with M onte Carlo sim ulations based on realistic LIG O and IceCube event distributions. W e estim ated a typical false alarm rate for the analysis to be 1 event per 435 years. This is signicantly sm aller than the false alarm ratesofthe individualdetectors.