The Gravity Collective: A Search for the Electromagnetic Counterpart to the Neutron Star–Black Hole Merger GW190814
The Gravity Collective: A Search for the Electromagnetic Counterpart to the Neutron Star–Black Hole Merger GW190814
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DOI：
10.3847/1538-4357/ac23c6
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发表时间：
2021-06
期刊：
影响因子：
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通讯作者：
C. Kilpatrick;D. Coulter;I. Arcavi;T. Brink;G. Dimitriadis;A. Filippenko;R. Foley;D. Howell
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文献类型：
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作者：
C. Kilpatrick;D. Coulter;I. Arcavi;T. Brink;G. Dimitriadis;A. Filippenko;R. Foley;D. Howell
我们展示了利用卡茨曼自动成像望远镜、拉斯坎布雷斯天文台全球望远镜网络、尼克尔望远镜、斯沃普望远镜以及撒切尔望远镜对来自中子星 - 黑洞（NSBH）并合事件GW190814的LIGO/处女座引力波（GW）信号所进行的光学后续成像观测结果。我们搜索了GW190814的定位区域（90%置信度下最佳定位区域为19平方度），覆盖总面积达51平方度，占二维定位区域的94.6%。通过分析189个我们认为可能是NSBH并合事件对应体的瞬变源的特性，包括它们的位置、距并合的发现时间、光谱、可能的宿主星系红移以及光度演化，我们得出结论：这些天体中没有一个可能与GW190814相关联。基于这一发现，我们考虑了GW190814的电磁对应体可能具有的光学特性，包括可能的千新星和短伽马射线暴余辉。利用我们后续成像的联合限制条件，我们得出结论：一个r波段衰减率为0.68星等/天（类似于千新星AT 2017gfo）的对应体，其绝对星等峰值最多为 -17.8星等（50%置信度）。我们的数据对“红色”千新星没有约束作用，并以30%置信度排除了质量大于0.5倍太阳质量的“蓝色”千新星。我们强烈排除了所有已知类型的、观测角度小于17°的短伽马射线暴余辉，假设初始喷流张角约为5.2°，且爆炸能量和环绕爆发物质的密度与文献中所研究的余辉相似。最后，我们探讨了GW190814在活动星系核的吸积盘中并合的可能性，我们在定位区域发现了四个活动星系核，但在这些源中没有发现任何可能的对应体。
We present optical follow-up imaging obtained with the Katzman Automatic Imaging Telescope, Las Cumbres Observatory Global Telescope Network, Nickel Telescope, Swope Telescope, and Thacher Telescope of the LIGO/Virgo gravitational wave (GW) signal from the neutron star–black hole (NSBH) merger GW190814. We searched the GW190814 localization region (19 deg2 for the 90th percentile best localization), covering a total of 51 deg2 and 94.6% of the two-dimensional localization region. Analyzing the properties of 189 transients that we consider as candidate counterparts to the NSBH merger, including their localizations, discovery times from merger, optical spectra, likely host galaxy redshifts, and photometric evolution, we conclude that none of these objects are likely to be associated with GW190814. Based on this finding, we consider the likely optical properties of an electromagnetic counterpart to GW190814, including possible kilonovae and short gamma-ray burst afterglows. Using the joint limits from our follow-up imaging, we conclude that a counterpart with an r-band decline rate of 0.68 mag day−1, similar to the kilonova AT 2017gfo, could peak at an absolute magnitude of at most −17.8 mag (50% confidence). Our data are not constraining for “red” kilonovae and rule out “blue” kilonovae with M > 0.5 M ⊙ (30% confidence). We strongly rule out all known types of short gamma-ray burst afterglows with viewing angles <17° assuming an initial jet opening angle of ∼5.°2 and explosion energies and circumburst densities similar to afterglows explored in the literature. Finally, we explore the possibility that GW190814 merged in the disk of an active galactic nucleus, of which we find four in the localization region, but we do not find any candidate counterparts among these sources.