  Neutron stars (NS) and black holes (BH) are sources of gravitational waves
(GW) and the investigation of young isolated radio-quiet NS can in principle
lead to constraints of the equation of state (EoS). The GW signal of merging
NSs critically depends on the EoS. However, unlike radio pulsars young isolated
radio-quiet neutron stars are hard to detect and only seven of them are known
so far. Furthermore, for GW projects it is necessary to confine regions in the
sky where and of which quantity sources of GW can be expected. We suggest
strategies for the search for young isolated radio-quiet NSs. One of the
strategies is to look for radioactivities which are formed during a supernova
(SN) event and are detectable due to their decay. Radioactivities with half
lives of ~1 Myr can indicate such an event while other remnants like nebulae
only remain observable for a few kyrs. Here we give a brief overview of our
strategies and discuss advantages and disadvantages
