This is preprint of a paper published in Class. Quantum Grav.,
vol. 22, No 18 (21 September 2005), S1243–S1254
Abstract We have analyzed three data sets, each 2 days long, of the EXPLORER resonant bar detector. We have searched for continuous gravitationalwave signals from spinning neutron stars. Our data analysis technique was based on the maximum likelihood detection method. We briefly describe the theoretical methods that we used in our search and we present results of the search. The main outcome of our analysis is an upper limit of 1×10^{22} for the dimensionless amplitude of a continuous gravitationalwave signal. The upper limit is for any source location in the sky, any polarization of the wave and for signals of frequency from 921.00 Hz to 921.76 Hz and with spin down from 2.36 ×10^{8} Hz s^{1} to +2.36 ×10^{8} Hz s^{1}. 
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Figure 1: Quality of the EXPLORER data. The xaxis gives the number of the 11hour block of data from the 13day data run. The top panel are the box plots for each block of data. The middle panel is the spectrogram of the data. Spectrogram contains spectrum of each block of data. The bottom panel gives results of the KS test. The vertical lines indicate beginning and end of each search that we have performed. 
Figure 2:
Twosided spectral density of the three 2day stretches of EXPLORER data that were analyzed. 
Search  Northern hemisphere  Southern hemisphere 
I  15663  21601 
II  9883  11666 
III  18776  23850 
Table 1: Number of triggers for the three searches of EXPLORER data. 
Maximal signaltonoise ratios  
Search 




 
I  8.01  8.19  7.68  8.02  7.35  
II  8.28  8.29  8.05  7.91  7.48  
III  8.48  8.45  7.38  8.90  7.70 
Table 2: Maximal signaltonoise ratios of events at various stages of data analysis procedure. The maxima are quoted for each stage of the search separately and in general they correspond to different triggers. "Linear parametrization" means search using linear parametrization introduced in Section 2.3, ästrophysical parametrization" means verification using astrophysical parameters and precise ephemeris of the detector, "different data" denotes verification in a different set of data, "longer data" means verification in 4day stretch of data, "all data" means verification in the whole 13day set of data. 
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