Trapped and excited w modes of stars with a phase transition and R>=5M
Trapped and excited w modes of stars with a phase transition and R>=5M
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具有相变且 R>=5M 的恒星的俘获和激发 w 模式
DOI：
10.1103/physrevd.63.124002
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发表时间：
2001
影响因子：
5
通讯作者：
Zeferino Andrade
中科院分区：
文献类型：
--
作者：
Zeferino Andrade
计算了具有一阶相变（密度不连续）的恒星的被困W模，并研究了扰动壳层对这些恒星的某些模的激发。注意力仅限于奇奇偶校验（"轴向“）$w$-模式。以$R$为星星的半径，$M$为质量，$Ri $为内核的半径，$Mi $为内核的质量，证明了只要$Ri/Mi <2.6$，$R/Mi = 5$的恒星可以有多个w-模.最小阻尼$w$-模式的激励被确认为几个模型。然而，所有这些恒星只能存在于两个相的密度之比大于$\sim 46$的情况下。我们还证明了具有相变和给定的$R/M$值的恒星可以比具有相同$R/M$值的均匀单密度星星具有更多的捕获模，只要$R/M$和$R_{i}/M_{i}$都小于3。如果相变非常快，大多数具有捕获模式的恒星对径向振荡是不稳定的。我们计算不稳定的时间，并发现它是可比的阻尼的$W$模式激发在大多数情况下，$W $模式激发是可能的。另一方面，如果相变是缓慢的，所有的恒星都是稳定的径向振荡。
The trapped $w$-modes of stars with a first order phase transition (a density discontinuity) are computed and the excitation of some of the modes of these stars by a perturbing shell is investigated. Attention is restricted to odd parity (``axial'') $w$-modes. With $R$ the radius of the star, $M$ its mass, $R_{i}$ the radius of the inner core and $M_{i}$ the mass of such core, it is shown that stars with $R/M\geq 5$ can have several trapped $w$-modes, as long as $R_{i}/M_{i}<2.6$. Excitation of the least damped $w$-mode is confirmed for a few models. All of these stars can only exist however, for values of the ratio between the densities of the two phases, greater than $\sim 46$. We also show that stars with a phase transition and a given value of $R/M$ can have far more trapped modes than a homogeneous single density star with the same value of $R/M$, provided both $R/M$ and $R_{i}/M_{i}$ are smaller than 3. If the phase transition is very fast, most of the stars with trapped modes are unstable to radial oscillations. We compute the time of instability, and find it to be comparable to the damping of the $w$-mode excited in most cases where $w$-mode excitation is likely. If on the other hand the phase transition is slow, all the stars are stable to radial oscillations.