Neutron-star Radius Constraints from GW170817 and Future Detections
Neutron-star Radius Constraints from GW170817 and Future Detections
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DOI：
10.3847/2041-8213/aa9994
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发表时间：
2017-12-01
影响因子：
7.9
通讯作者：
Stergioulas, Nikolaos
中科院分区：
文献类型：
--
作者：
Bauswein, Andreas;Just, Oliver;Stergioulas, Nikolaos
我们介绍了一种新的、强有力的方法来约束中子星(NSS)的性质。我们的结果表明，如果合并没有像相关电磁辐射解释所暗示的那样导致迅速崩塌，那么GW170817的总质量对恒星半径提供了可靠的约束。质量为1.6M圆点的非旋转NSS的半径R-1.6可以被约束为大于10.68(-0.04)(+0.15)公里，非旋转最大质量构型的半径R-max必须大于9.60(-0.03)(+0.14)公里。我们指出，对未来事件的检测将进一步改善这些限制。此外，我们还表明，一个具有合并残余物迅速崩塌特征的未来事件将从上方对NSS的NS半径和从上方对NSS的最大质量M-max建立更强的约束。这些约束特别强大，因为它们只需要测量啁啾质量，并区分合并残留物的立即坍塌和延迟坍塌，这可以从电磁信号或甚至从存在/不存在环形引力波(GW)信号中推断出来。这一前景加强了我们约束NS性质的新方法的情况，该方法直接适用于未来的GW事件，并伴随着电磁对应观测。我们强调，这个过程是一种从GW探测中限制NS半径的新方法，独立于现有的从晚期激发相或合并后振荡中推断半径信息的努力，并且它不需要特别响亮的GW事件。
We introduce a new, powerful method to constrain properties of neutron stars (NSs). We show that the total mass of GW170817 provides a reliable constraint on the stellar radius if the merger did not result in a prompt collapse as suggested by the interpretation of associated electromagnetic emission. The radius R-1.6 of nonrotating NSs with a mass of 1.6 M circle dot can be constrained to be larger than 10.68(-0.04)(+0.15) km, and the radius R-max of the nonrotating maximum-mass configuration must be larger than 9.60(-0.03)(+0.14) km. We point out that detections of future events will further improve these constraints. Moreover, we show that a future event with a signature of a prompt collapse of the merger remnant will establish even stronger constraints on the NS radius from above and the maximum mass M-max of NSs from above. These constraints are particularly robust because they only require a measurement of the chirp mass and a distinction between prompt and delayed collapse of the merger remnant, which may be inferred from the electromagnetic signal or even from the presence/absence of a ringdown gravitational-wave (GW) signal. This prospect strengthens the case of our novel method of constraining NS properties, which is directly applicable to future GW events with accompanying electromagnetic counterpart observations. We emphasize that this procedure is a new way of constraining NS radii from GW detections independent of existing efforts to infer radius information from the late inspiral phase or post-merger oscillations, and it does not require particularly loud GW events.