论文标题
Sgra $^{*} $旋转和质量估算通过检测极大的质量比率Inspiral
SgrA$^{*}$ spin and mass estimates through the detection of an extremely large mass-ratio inspiral
论文作者
论文摘要
估计$ {\ rm sgra^\ ast} $的旋转是我们在理解银河系中心面临的当前挑战之一。在目前的工作中，我们表明，棕色矮人在$ {\ rm sgra^\ ast} $上发出的引力波（GWS）将使我们能够衡量$ {\ rm sgra^\ ast} $的质量和旋转。这样的系统被称为极大的大量比率灵感（XMRIS），并有望在我们的银河中心丰富而响亮的来源。我们认为XMRI具有固定的轨道倾斜度和$ {\ rm sgra^\ ast} $（$ s $）的不同旋转在0.1和0.9之间。在这两种情况下，我们都会获得预期由丽莎和天气等太空GW探测器检测到的圆形和偏心XMRI的数量。我们发现，如果轨道是偏心的，那么我们希望始终在频段中有几个XMRI，而对于几乎圆形的XMRI，我们只希望如果$ {\ rm sgra^\ ast} $具有很高的旋转，我们只希望有一个源。稍后，我们执行Fisher矩阵分析，以表明，通过检测单个XMRI $ {\ rm sgra^\ ast} $的质量可以通过$ 10^{ - 2} \，\ text {m} _ {\ odot} $准确地确定$ 10^{ - 2} \，同时可以用$ 10^$ 10^ - - $ 10^{ - 4} $取决于XMRI的轨道参数。
Estimating the spin of ${\rm SgrA^\ast}$ is one of the current challenges we face in understanding the center of our Galaxy. In the present work, we show that detecting the gravitational waves (GWs) emitted by a brown dwarf inspiraling around ${\rm SgrA^\ast}$ will allow us to measure the mass and the spin of ${\rm SgrA^\ast}$ with unprecedented accuracy. Such systems are known as extremely large mass-ratio inspirals (XMRIs) and are expected to be abundant and loud sources in our galactic center. We consider XMRIs with a fixed orbital inclination and different spins of ${\rm SgrA^\ast}$ ($s$) between 0.1 and 0.9. For both cases, we obtain the number of circular and eccentric XMRIs expected to be detected by space-borne GW detectors like LISA and TianQin. We find that if the orbit is eccentric, then we expect to always have several XMRIs in band while for almost circular XMRIs, we only expect to have one source in band if ${\rm SgrA^\ast}$ is highly spinning. We later perform a Fisher matrix analysis to show that by detecting a single XMRI the mass of ${\rm SgrA^\ast}$ can be determined with an accuracy of the order $10^{-2}\,\text{M}_{\odot}$, while the spin can be measured with an accuracy between $10^{-7}$ and $10^{-4}$ depending on the orbital parameters of the XMRI.
