A Novel Search Technique for Low-Frequency Periodic Gravitational Waves

TL;DR

This paper introduces a new data processing method for detecting low-frequency continuous gravitational waves from neutron stars, which simplifies the search and improves sensitivity using Earth's orbital symmetry.

Contribution

The paper presents a novel technique leveraging Earth's orbital symmetry to enhance gravitational wave searches, reducing parameter space and improving sensitivity with manageable computational costs.

Findings

Reduces search parameter space significantly.

Achieves sensitivity comparable or superior to existing methods.

Requires processing time similar to data acquisition period.

Abstract

We quantify the advantages of a recently proposed data processing technique to search for continuous gravitational wave (GW) signals from isolated rotating asymmetric neutron stars in data measured by ground-based GW interferometers. This technique relies on the symmetry of the motion around the Sun of an Earth-bound gravitational wave interferometer. By multiplying the measured data time series with a half-year time-shifted copy of it, we obtain two advantages: (i) the main Doppler phase modulation of a monochromatic gravitational wave signal is exactly removed, and (ii) the signal in the product data are located at twice the GW signal frequency. The first significantly reduces the size of the signal's parameter space over which a search is to be performed. The second is advantageous at low frequencies; we find that, with currently available computer processing speeds, this technique is capable of achieving sensitivity that is comparable to or even better than coherent and other possibly non-coherent methods. Further, since our proposed method is implemented over a year-long data segment, it requires processing time comparable to the data acquisition time of currently available computers.