Narrow-band search of continuous gravitational-wave signals from Crab and Vela pulsars in Virgo VSR4 data
Narrow-band search of continuous gravitational-wave signals from Crab and Vela pulsars in Virgo VSR4 data
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DOI：
10.1103/physrevd.91.022004
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发表时间：
2015-01-21
影响因子：
5
通讯作者：
Zweizig, J.
中科院分区：
文献类型：
--
作者：
Aasi, J.;Abbott, B. P.;Zweizig, J.
在本文中，我们介绍了在 Virgo VSR4 数据上对来自 Crab 和 Vela 脉冲星的连续引力波信号进行相干窄带搜索的结果。为了考虑到引力波频率与两倍恒星旋转频率之间可能存在的微小不匹配（从电磁脉冲率的测量中推断出），已经在两倍恒星旋转频率周围的 0.02 Hz 范围内搜索了两颗脉冲星。没有发现信号的证据，并且假设偏振参数完全未知，并且已知它们具有一定的不确定性，如从脉冲星风鸟居的 X 射线观测中得出的那样，已经计算出 95% 的置信水平上限。对于 Vela 来说，上限与自旋下降极限相当，计算时假设所有观察到的自旋下降都是由于引力波的发射造成的。对于 Crab 来说，上限大约比旋转限制低 2 倍，相对于过去的分析来说是一个显着的改进。这是窄带搜索中首次显着克服自旋下降限制。
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.