论文标题
Vela Pulsar的小故障和其他旋转不规则性
Small glitches and other rotational irregularities of the Vela pulsar
论文作者
论文摘要
小故障是中子星的旋转速率$ν$突然增加，被认为是由恒星内的中子超流动驱动的。 Vela Pulsar的故障率相对较高，自1968年观察开始以来报告了21个事件。这些事件是最大的已知故障之一（其中17个具有尺寸$δν/ν/ν\ geq10^{ - 6} $），并且表现出非常相似的特征。这种相似性，结合出大小故障的规律性，将Vela变成了这种类型的小故障行为的原型。另一方面，其最小故障的特性尚未清楚地确定。 1981年至2005年在山上的无线电天文台进行了对Vela Pulsar的高度观测。进行了自动系统搜索，该搜索研究了是否在任何给定时间进行旋转频率$ν$和/或旋转率$ \dotν$的重大变化。我们找到了两个新的故障，其中$（5.55 \ pm0.03）\ times10^{ - 9} $和$（38 \ pm4）\ times10^{ - 9} $。除了这两个小故障事件外，我们的研究还揭示了所有可能的签名的许多事件（即$Δν$和$Δ\dotν$标志的组合），所有这些都为$ |δν|/ν|/ν|/ν<10^{ - 9} $，这有助于Vela的时机噪声。与许多其他小故障脉冲星相比，Vela Pulsar的小故障含量不足，这似乎是真实的，而不是观察性偏见的结果。除了典型的故障外，脉冲星的平滑旋转还受到几乎连续的活动的影响，该活动可以部分地以$ν$，$ \ dot {ν，} $或两者兼而有之的小台阶变化。模拟表明，旋转相的连续徘徊在红色光谱之后可以模仿定时残差的这种阶梯状变化。
Glitches are sudden increases in the rotation rate $ν$ of neutron stars, which are thought to be driven by the neutron superfluid inside the star. The Vela pulsar presents a comparatively high rate of glitches, with 21 events reported since observations began in 1968. These are amongst the largest known glitches (17 of them have sizes $Δν/ν\geq10^{-6}$) and exhibit very similar characteristics. This similarity, combined with the regularity with which large glitches occur, has turned Vela into an archetype of this type of glitching behaviour. The properties of its smallest glitches, on the other hand, are not clearly established. High-cadence observations of the Vela pulsar were taken between 1981 and 2005 at the Mount Pleasant Radio Observatory. An automated systematic search was carried out that investigated whether a significant change of spin frequency $ν$ and/or the spin-down rate $\dotν$ takes place at any given time. We find two new glitches, with respective sizes $Δν/ν$ of $(5.55\pm0.03)\times10^{-9}$ and $(38\pm4)\times10^{-9}$. In addition to these two glitch events, our study reveals numerous events of all possible signatures (i.e. combinations of $Δν$ and $Δ\dotν$ signs), all of them small with $|Δν|/ν<10^{-9}$, which contribute to the Vela timing noise. The Vela pulsar presents an under-abundance of small glitches compared to many other glitching pulsars, which appears genuine and not a result of observational biases. In addition to typical glitches, the smooth spin-down of the pulsar is also affected by an almost continuous activity that can be partially characterised by small step-like changes in $ν$, $\dot{ν,}$ or both. Simulations indicate that a continuous wandering of the rotational phase, following a red spectrum, could mimic such step-like changes in the timing residuals.
