Isolated spinning neutron stars, asymmetric with respect to their rotation axis, are expected to be sourcesof continuous gravitational waves. The most sensitive searches for these sources are based on accuratematched filtering techniques that assume the continuous wave to be phase locked with the pulsar beamedemission. While matched filtering maximizes the search sensitivity, a significant signal-to-noise ratio losswill happen in the case of a mismatch between the assumed and the true signal phase evolution. Narrow-band algorithms allow for a small mismatch in the frequency and spin-down values of the pulsar whilecoherently integrating the entire dataset. In this paper, we describe a narrow-band search using LIGO O2data for the continuous wave emission of 33 pulsars. No evidence of a continuous wave signal is found, andupper limits on the gravitational wave amplitude over the analyzed frequency and spin-down rangesare computed for each of the targets. In this search, we surpass the spin-down limit, namely, the maximumrotational energy loss due to gravitational waves emission for some of the pulsars already present in theLIGO O1 narrow-band search, such as J1400−6325,J1813−1246,J1833−1034,J1952þ3252, andfor new targets such as J0940−5428and J1747−2809. For J1400−6325,J1833−1034, andJ1747−2809, this is the first time the spin-down limit is surpassed.
Narrow-band search for gravitational waves from known pulsars using the second LIGO observing run
Acernese F;Barone F;Romano R;
2019-01-01
Abstract
Isolated spinning neutron stars, asymmetric with respect to their rotation axis, are expected to be sourcesof continuous gravitational waves. The most sensitive searches for these sources are based on accuratematched filtering techniques that assume the continuous wave to be phase locked with the pulsar beamedemission. While matched filtering maximizes the search sensitivity, a significant signal-to-noise ratio losswill happen in the case of a mismatch between the assumed and the true signal phase evolution. Narrow-band algorithms allow for a small mismatch in the frequency and spin-down values of the pulsar whilecoherently integrating the entire dataset. In this paper, we describe a narrow-band search using LIGO O2data for the continuous wave emission of 33 pulsars. No evidence of a continuous wave signal is found, andupper limits on the gravitational wave amplitude over the analyzed frequency and spin-down rangesare computed for each of the targets. In this search, we surpass the spin-down limit, namely, the maximumrotational energy loss due to gravitational waves emission for some of the pulsars already present in theLIGO O1 narrow-band search, such as J1400−6325,J1813−1246,J1833−1034,J1952þ3252, andfor new targets such as J0940−5428and J1747−2809. For J1400−6325,J1833−1034, andJ1747−2809, this is the first time the spin-down limit is surpassed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
