Method for all-sky searches of continuous gravitational wave signals   using the frequency-Hough transform
  In this paper we present a hierarchical data analysis pipeline for all-sky searches of continuous gravitational wave signals, like those emitted by spinning neutron stars asymmetric with respect to the rotation axis, with unknown position, rotational frequency and spin-down. The core of the pipeline is an incoherent step based on a particularly efficient implementation of the Hough transform, that we call frequency-Hough, that maps the data time-frequency plane to the source frequency/spin-down plane for each fixed direction in the sky. Theoretical ROCs and sensitivity curves are computed and the dependency on various thresholds is discussed. A comparison of the sensitivity loss with respect to an "optimal" method is also presented. Several other novelties, with respect to other wide-parameter analysis pipelines, are also outlined. They concern, in particular, the construction of the grid in the parameter space, with over-resolution in frequency and parameter refinement, candidate selection and various data cleaning steps which are introduced to improve search sensitivity and rejection of false candidates. 
Pia Astone, Alberto Colla, Sabrina D'Antonio, Sergio Frasca and   Cristiano Palomba
astro-ph.IM