Detection of periodic gravitational wave sources by Hough transform in the frequency and spin down plane

TL;DR

This paper introduces a new frequency Hough transform method for detecting periodic gravitational wave sources, improving sensitivity and reducing false candidates compared to traditional sky Hough methods.

Contribution

The paper presents a novel frequency Hough transform technique that enhances frequency resolution and minimizes false positives in gravitational wave searches.

Findings

Frequency Hough improves frequency resolution without high computational cost.

The method reduces false candidates caused by local disturbances.

Simulations show advantages over traditional sky Hough procedures.

Abstract

In the hierarchical search for periodic sources of gravitational waves, the candidate selection, in the incoherent step, can be performed with Hough transform procedures. In this paper we analyze the problem of sensitivity loss due to discretization of the parameters space vs computing cost, comparing the properties of the sky Hough procedure with those of a new frequency Hough, which is based on a transformation from the time - observed frequency plane to the source frequency - spin down plane. Results on simulated peak maps suggest various advantages in favor of the use of the frequency Hough. The ones which show up to really make the difference are 1) the possibility to enhance the frequency resolution without relevantly affecting the computing cost. This reduces the digitization effects; 2) the excess of candidates due to local disturbances in some places of the sky map. They do not affect the new analysis because each map is constructed for only one position in the sky. Pacs. numbers: 04.80Nn,07.05Kf,97.60Jd 1.