The electromagnetic signals of compact binary mergers
The electromagnetic signals of compact binary mergers
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DOI：
10.1093/mnras/stt037
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发表时间：
2013-04-01
影响因子：
4.8
通讯作者：
Rosswog, Stephan
中科院分区：
文献类型：
--
作者：
Piran, Tsvi;Nakar, Ehud;Rosswog, Stephan
紧凑的双星合并是引力波（GW）的主要来源，是当前和下一代探测器的目标。问题是“什么是可观察到的电磁（EM）签名的一个紧凑的二元合并？是一个有趣的问题，对寻求全球Ws有着至关重要的影响。我们提出了一个大型的数值模拟，集中在EM信号出现的动态喷射subrelativistic材料。这些流出物在一天的时间尺度上产生macronovae -由放射性衰变提供动力的短寿命红外（IR）到紫外（UV）信号。就像在普通的超新星中一样，这种流出物与周围物质的相互作用不可避免地导致了长期的残留物。我们计算预期的无线电信号，这些遗迹的时间尺度超过一年，当subrelativistic喷出物占主导地位的排放。我们讨论了它们在1.4 GHz和150 MHz的可探测性，并将其与短伽马射线爆发孤儿余辉（由这种外流的不同成分产生）的可探测性的更新估计进行比较。我们发现，发生在先进GW探测器（300 Mpc）的探测视界处的具有与银河系中子星星二元群相似特征的合并（相似的质量和典型的绕合并银河系盘密度，类似于1厘米（-3）），产生类似于50 [300] μ Jy的1.4 GHz [150 MHz]信号，持续数年。在几周的时间尺度上，信号主要是由温和和/或极端相对论性的外流，这是不占我们的模拟，预计将更加明亮。即将进行的所有天空调查预计将在任何给定时间检测几十个，甚至可能更多的合并残留物，从而甚至在先进的GW探测器投入使用之前为合并率提供可靠的下限。macronovae信号来自IR到UV范围内的相同距离峰值，其观测到的量级可能在合并后约10小时明亮至22-23，但如果不透明度较大，则会变暗，变红和更长。
Compact binary mergers are prime sources of gravitational waves (GWs), targeted by current and next generation detectors. The question 'what is the observable electromagnetic (EM) signature of a compact binary merger?' is an intriguing one with crucial consequences to the quest for GWs. We present a large set of numerical simulations that focus on the EM signals that emerge from the dynamically ejected subrelativistic material. These outflows produce on a time-scale of a day macronovae - short-lived infrared (IR) to ultraviolet (UV) signals powered by radioactive decay. Like in regular supernovae the interaction of this outflow with the surrounding matter inevitably leads to a long-lasting remnant. We calculate the expected radio signals of these remnants on time-scales longer than a year, when the subrelativistic ejecta dominate the emission. We discuss their detectability in 1.4 GHz and 150 MHz and compare it with an updated estimate of the detectability of short gamma-ray bursts' orphan afterglows (which are produced by a different component of this outflow). We find that mergers with characteristics similar to those of the Galactic neutron star binary population (similar masses and typical circummerger Galactic disc density of similar to 1 cm(-3)) that take place at the detection horizon of advanced GW detectors (300 Mpc) yield 1.4 GHz [150 MHz] signals of similar to 50 [300] mu Jy, for several years. The signal on time-scales of weeks is dominated by the mildly and/or ultrarelativistic outflow, which is not accounted for by our simulations, and is expected to be even brighter. Upcoming all sky surveys are expected to detect a few dozen, and possibly more, merger remnants at any given time thereby providing robust lower limits to the mergers rate even before the advanced GW detectors become operational. The macronovae signals from the same distance peak in the IR to UV range at an observed magnitude that may be as bright as 22-23 about 10 h after the merger but dimmer, redder and longer if the opacity is larger.