In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown and that they are known with some uncertainty, as derived from x-ray observations of the pulsar wind torii. For Vela the upper limits are comparable to the spin-down limit, computed assuming that all the observed spin-down is due to the emission of gravitational waves. For Crab the upper limits are about a factor of 2 below the spin-down limit, and represent a significant improvement with respect to past analysis. This is the first time the spin-down limit is significantly overcome in a narrow-band search.

Narrow-band search of continuous gravitational-wave signals from Crab and Vela pulsars in Virgo VSR4 data

BASTI, ANDREA;BOSCHI, VALERIO;DEL POZZO, WALTER;DI LIETO, ALBERTO;FERRANTE, ISIDORO;FIDECARO, FRANCESCO;PASSAQUIETI, ROBERTO;POGGIANI, ROSA;RAZZANO, MASSIMILIANO;TONELLI, MAURO;
2015-01-01

Abstract

In this paper we present the results of a coherent narrow-band search for continuous gravitational-wave signals from the Crab and Vela pulsars conducted on Virgo VSR4 data. In order to take into account a possible small mismatch between the gravitational-wave frequency and two times the star rotation frequency, inferred from measurement of the electromagnetic pulse rate, a range of 0.02 Hz around two times the star rotational frequency has been searched for both the pulsars. No evidence for a signal has been found and 95% confidence level upper limits have been computed assuming both that polarization parameters are completely unknown and that they are known with some uncertainty, as derived from x-ray observations of the pulsar wind torii. For Vela the upper limits are comparable to the spin-down limit, computed assuming that all the observed spin-down is due to the emission of gravitational waves. For Crab the upper limits are about a factor of 2 below the spin-down limit, and represent a significant improvement with respect to past analysis. This is the first time the spin-down limit is significantly overcome in a narrow-band search.
2015
J., Aasi; Abbott, B.  . P.; R., Abbott; T., Abbott; Abernathy, M.  . R.; F., Acernese; K., Ackley; C., Adams; T., Adams; T., Adams; P., Addesso; Adhik...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/693264
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