Searching for Pulsars in Close Binary Systems

We present a detailed mathematical analysis of the Fourier response of binary pulsar signals whose frequencies are modulated by circular orbital motion. The fluctuation power spectrum of such signals is found to be \nu_orb-periodic over a compact frequency range, where \nu_orb denotes orbital frequency. Subsequently, we consider a wide range of binary systems with circular orbits and short orbital periods, and present a Partial Coherence Recovery Technique for searching for binary millisecond X-ray and radio pulsars. We use numerical simulations to investigate the detectability of pulsars in such systems with P_orb ~ 6 hours, using this technique and three widely used pulsar search methods. These simulations demonstrate that the Partial Coherence Recovery Technique is on average several times more sensitive at detecting pulsars in close binary systems when the data span is more than 2 orbital periods. The systems one may find using such a method can be used to improve the constraints on the coalescence rate of compact objects and they also represent those systems most likely to be detected with gravitational wave detectors such as LISA

Binary and Millisecond Pulsars

We review the main properties, demographics and applications of binary and millisecond radio pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1700. There are now 80 binary and millisecond pulsars associated with the disk of our Galaxy, and a further 103 pulsars in 24 of the Galactic globular clusters. Recent highlights have been the discovery of the first ever double pulsar system and a recent flurry of discoveries in globular clusters, in particular Terzan 5.Comment: 77 pages, 30 figures, available on-line at http://www.livingreviews.org/lrr-2005-

Searching for pulsars in close circular binary systems

We present a detailed mathematical analysis of the Fourier response of binary pulsar signals whose frequencies are modulated by circular orbital motion. The fluctuation power spectrum of such signals is found to be \nu_orb-periodic over a compact frequency range, where \nu_orb denotes orbital frequency. Subsequently, we consider a wide range of binary systems with circular orbits and short orbital periods, and present a Partial Coherence Recovery Technique for searching for binary millisecond X-ray and radio pulsars. We use numerical simulations to investigate the detectability of pulsars in such systems with P_orb ~ 6 hours, using this technique and three widely used pulsar search methods. These simulations demonstrate that the Partial Coherence Recovery Technique is on average several times more sensitive at detecting pulsars in close binary systems when the data span is more than 2 orbital periods. The systems one may find using such a method can be used to improve the constraints on the coalescence rate of compact objects and they also represent those systems most likely to be detected with gravitational wave detectors such as LISA.Comment: Submitted to Astronomy & Astrophysic