A search for periodic gravitational-wave signals from isolated neutron stars in the NAUTILUS detector data is presented. We have analyzed half a year of data over the frequency band <922.2;923.2> Hz, the spindown range <−1.463×10−8;0> Hz/s and over the entire sky. We have divided the data into 2 day stretches and we have analyzed each stretch coherently using matched filtering. We have imposed a low threshold for the optimal detection statistic to obtain a set of candidates that are further examined for coincidences among various data stretches. For some candidates we have also investigated the change of the signal-to-noise ratio when we increase the observation time from two to four days. Our analysis has not revealed any gravitational-wave signals. Therefore we have imposed upper limits on the dimensionless gravitational-wave amplitude over the parameter space that we have searched. Depending on frequency, our upper limit ranges from 3.4×10−23 to 1.3×10−22. We have attempted a statistical verification of the hypotheses leading to our conclusions. We estimate that our upper limit is accurate to within 18%.
@article{arxiv.0809.0273,
title = {All-sky search of NAUTILUS data},
author = {P. Astone and M. Bassan and P. Bonifazi and K. M. Borkowski and R. J. Budzyński and A. Chincarini and E. Coccia and S. D'Antonio and M. Di Paolo Emilio and V. Fafone and S. Frasca and S. Foffa and G. Giordano and P. Jaranowski and W. Kondracki and A. Królak and M. Maggiore and A. Marini and Y. Minenkov and I. Modena and G. Modestino and A. Moleti and G. V. Pallottino and C. Palomba and R. Parodi and M. Pietka and G. Pizzella and H. J. Pletsch and L. Quintieri and F. Ricci and A. Rocchi and F. Ronga and R. Sturani and R. Terenzi and R. Vaccarone and M. Visco},
journal= {arXiv preprint arXiv:0809.0273},
year = {2008}
}