DATA-ANALYSIS OF GRAVITATIONAL-WAVE SIGNALS FROM SPINNING NEUTRON-STARS - THE SIGNAL AND ITS DETECTION - ART. NO. 063001

We present a theoretical background for the data analysis of the gravi tational-wave signals from spinning neutron stars for Earth-based lase r interferometric detectors. We introduce a detailed model of the sign al including both the frequency and the amplitude modulations. We incl ude the effects of the intrinsic frequency changes and the modulation of the frequency at the detector due to Earth's motion. We estimate th e effects of the star's proper motion and of relativistic corrections. Moreover we consider a signal consisting of two components correspond ing to a frequency f and twice that frequency. From the maximum likeli hood principle we derive the detection statistics for the signal and w e calculate the probability density function of the statistics. We obt ain the data analysis procedure to detect the signal and to estimate i ts parameters. We show that for optimal detection of the amplitude mod ulated signal we need four linear filters instead of one linear filter needed for a constant amplitude signal. Searching for the doubled fre quency signal increases further the number of linear filters by a fact or of 2. We indicate how the fast Fourier transform algorithm and resa mpling methods commonly proposed in the analysis of periodic signals c an be used to calculate the detection statistics for our signal. We fi nd that the probability density function of the detection statistics i s determined by one parameter: the optimal signal-to-noise ratio. We s tudy the signal-to-noise ratio by means of the Monte Carlo method fur all long-arm interferometers that are currently under construction. We show how our analysis can be extended to perform a joint search for p eriodic signals by a network of detectors and we perform a Monte Carlo study of the signal-to-noise ratio for a network of detectors. [S0556 -2821(98)00718-8].