TY - JOUR
T1 - Beating the Spin-Down Limit on Gravitational Wave Emission From the Vela Pulsar
AU - Aston, Stuart
AU - Aylott, Ann
AU - Chalkley, Eleanor
AU - Cruise, Adrian
AU - Freise, Andreas
AU - Fulda, Paul
AU - Lodhia, Deepali
AU - Mandel, Ilya
AU - Smith, Robert
AU - Nelson, John
AU - Vecchio, Alberto
PY - 2011/8/1
Y1 - 2011/8/1
N2 - We present direct upper limits on continuous gravitational wave emission from the Vela pulsar using data from the Virgo detector's second science run. These upper limits have been obtained using three independent methods that assume the gravitational wave emission follows the radio timing. Two of the methods produce frequentist upper limits for an assumed known orientation of the star's spin axis and value of the wave polarization angle of, respectively, 1.9 x 10(-24) and 2.2 x 10(-24), with 95% confidence. The third method, under the same hypothesis, produces a Bayesian upper limit of 2.1 x 10(-24), with 95% degree of belief. These limits are below the indirect spin-down limit of 3.3 x 10(-24) for the Vela pulsar, defined by the energy loss rate inferred from observed decrease in Vela's spin frequency, and correspond to a limit on the star ellipticity of similar to 10(-3). Slightly less stringent results, but still well below the spin-down limit, are obtained assuming the star's spin axis inclination and the wave polarization angles are unknown.
AB - We present direct upper limits on continuous gravitational wave emission from the Vela pulsar using data from the Virgo detector's second science run. These upper limits have been obtained using three independent methods that assume the gravitational wave emission follows the radio timing. Two of the methods produce frequentist upper limits for an assumed known orientation of the star's spin axis and value of the wave polarization angle of, respectively, 1.9 x 10(-24) and 2.2 x 10(-24), with 95% confidence. The third method, under the same hypothesis, produces a Bayesian upper limit of 2.1 x 10(-24), with 95% degree of belief. These limits are below the indirect spin-down limit of 3.3 x 10(-24) for the Vela pulsar, defined by the energy loss rate inferred from observed decrease in Vela's spin frequency, and correspond to a limit on the star ellipticity of similar to 10(-3). Slightly less stringent results, but still well below the spin-down limit, are obtained assuming the star's spin axis inclination and the wave polarization angles are unknown.
U2 - 10.1088/0004-637X/737/2/93
DO - 10.1088/0004-637X/737/2/93
M3 - Article
SN - 1538-4357
VL - 737
SP - 93
JO - The Astrophysical Journal
JF - The Astrophysical Journal
IS - 2
M1 - 93
ER -