MS. ANURADHA GUPTA

We probe the benefits of specifying orbital and spin angular momentum vectors in an invariant frame associated with the initial direction of total angular momentum {\bf j_0} while performing gravitational wave (GW) phasing for unequal mass spinning compact binaries. We evolve such isolated binaries having spin-orbit misalignment = 160 deg until their GWs enter frequency windows of inter-ferometric detectors. It turns out that the dominant black hole spin orientations in such Neutron Star-Black Hole binaries are more likely to be = 90 deg from {\bf j_0} when they spiral into Advanced LIGO frequency window. Similar conclusions apply for binary Black Holes provided their total mass and mass ratio are = 30Msun and = 6, respectively. However, it is difficult to provide similar bounds on dominant black hole spin orientations for such binaries having spin-orbit misalignment > 160 deg and interesting aspects of their orbital evolutions are explored in detail. Unfortunately, dominant spin orientations in the traditional GW phasing approach do not enjoy above constraints. Invoking these inferences, we argue that the number of templates, required to densely cover the angular sectors of associated signal manifolds, should be substantially smaller in our GW phasing prescription.