On the resonant detectors sensitivity to continuous signals

For a continuous (periodic or quasi-periodic) signal of amplitude at the frequency
the squared modulus of the Fourier Transform provides
with a noise contribution of
,
being
the two-sided noise power spectrum of the detector
(measured in 1/Hz).
Thus the SNR for periodic signals is:
The Eq. holds if the instantaneous frequency of the continuous signal at the detector is known. The analysis procedure in this case is ``coherent'', since the phase information contained in the data is used and the sensitivity (in amplitude) increases with the square-root of the time. For periodic waves the sensitivity of a bar detector at its resonances is given by:

is the bar temperature; its mass; the merit factor; the resonance frequency of the mode; the observation time. After

For the

We have developed a procedure for the search of signals from periodic sources in the data of gravitational wave detectors. We have analyzed data of the resonant detector Explorer, searching for sources located in the Galactic Center (GC). No signals with amplitude greater than , in the range 921.32-921.38 Hz, were observed using data collected over a time period of 95.7 days, for a source located at hours and degrees. The procedure we have used can be extended for any assumed position in the sky and for a more general all-sky search, with the proper frequency correction to account for the spin-down and Doppler effects. The results are being printed on PRD (2001).