Searches for gravitational waves from known pulsars with S5 LIGO data

Source: arXiv

ABSTRACT We present a search for gravitational waves from 116 known millisecond and
young pulsars using data from the fifth science run of the LIGO detectors. For
this search ephemerides overlapping the run period were obtained for all
pulsars using radio and X-ray observations. We demonstrate an updated search
method that allows for small uncertainties in the pulsar phase parameters to be
included in the search. We report no signal detection from any of the targets
and therefore interpret our results as upper limits on the gravitational wave
signal strength. The most interesting limits are those for young pulsars. We
present updated limits on gravitational radiation from the Crab pulsar, where
the measured limit is now a factor of seven below the spin-down limit. This
limits the power radiated via gravitational waves to be less than ~2% of the
available spin-down power. For the X-ray pulsar J0537-6910 we reach the
spin-down limit under the assumption that any gravitational wave signal from it
stays phase locked to the X-ray pulses over timing glitches, and for pulsars
J1913+1011 and J1952+3252 we are only a factor of a few above the spin-down
limit. Of the recycled millisecond pulsars several of the measured upper limits
are only about an order of magnitude above their spin-down limits. For these
our best (lowest) upper limit on gravitational wave amplitude is 2.3x10^-26 for
J1603-7202 and our best (lowest) limit on the inferred pulsar ellipticity is
7.0x10^-8 for J2124-3358.

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Available from: Giancarlo Cella, Jul 05, 2015
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