Beating the spin-down limit on gravitational wave emission from the Vela pulsar
Beating the spin-down limit on gravitational wave emission from the Vela pulsar
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DOI：
10.1088/0004-637x/737/2/93
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发表时间：
2011-04
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我们提出了直接上限连续引力波发射船帆座脉冲星使用的数据从处女座探测器的第二次科学运行。这些上限是使用三种独立的方法获得的，这些方法假设引力波发射遵循无线电计时。其中两种方法产生的频率上限为一个假设的已知方位的星星的自旋轴和值的波偏振角，分别为1.9\ee {-24}$和2.2\ee {-24}$，95%的置信度。第三种方法，在相同的假设下，产生贝叶斯上限为2.1\ee {-24}$，置信度为95%。这些极限低于船帆座脉冲星的间接{\it spin-down limit} 3.3\ee {-24}$，由观测到的船帆座自旋频率下降推断的能量损失率定义，对应于星星椭圆率的极限为$\sim 10^{-3}$。假设星星的自旋轴倾角和波的偏振角是未知的，得到的结果稍微不那么严格，但仍然远低于自旋下限。
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, $1.9\ee{-24}$ and $2.2\ee{-24}$, with 95% confidence. The third method, under the same hypothesis, produces a Bayesian upper limit of $2.1\ee{-24}$, with 95% degree of belief. These limits are below the indirect {\it spin-down limit} of $3.3\ee{-24}$ 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 $\sim 10^{-3}$. 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.