Estimation of the gravitational wave polarizations from a non template search

Abstract

Gravitational wave astronomy is just beginning, after the recent success of the four direct detections of binary black hole (BBH) mergers, the first observation from a binary neutron star inspiral and with the expectation of many more events to come. Given the possibility to detect waves from not perfectly modeled astrophysical processes, it is fundamental to be ready to calculate the polarization waveforms in the case of searches using non-template algorithms. In such case, the waveform polarizations are the only quantities that contain direct information about the generating process. We present the performance of a new valuable tool to estimate the inverse solution of gravitational wave transient signals, starting from the analysis of the signal properties of a non-template algorithm that is open to a wider class of gravitational signals not covered by template algorithms. We highlight the contributions to the wave polarization associated with the detector response, the sky localization and the polarization angle of the source. In this paper we present the performances of such method and its implications by using two main classes of transient signals, resembling the limiting case for most simple and complicated morphologies. Performances are encouraging, for the tested waveforms: the correlation between the original and the reconstructed waveforms spans from better than 80% for simple morphologies to better than 50% for complicated ones. For a not-template search this results can be considered satisfactory to reconstruct the astrophysical progenitor.