The mass of the stellar precursor of supernova (SN) 1987A and the burst of neutrinos observed at the moment of the explosion are consistent with the core-collapse formation of a neutron star. However, no compelling evidence for the presence in SN 1987A of a compact object of any kind has been found yet in any band of the electromagnetic spectrum, prompting questions on whether the neutron star survived and, if it did, on its properties. Starting from the analysis of recent Chandra observations, here we appraise the current observational situation. We derived limits on the X-ray luminosity of a compact object with a nonthermal, Crab-pulsar-like spectrum of the order of $\approx$$(1$-$5)\times10^{35}$ erg s$^{-1}$, corresponding to limits on the rotational energy loss of a possible X-ray pulsar in SN 1987A of $\approx$$(0.5$-$1.5)\times10^{38}$ erg s$^{-1}$. However, a much brighter X-ray source cannot be excluded if, as is likely, it is enshrouded in a cloud of absorbing matter with metallicity similar to that expected in the outer layers of a massive star towards the end of its life. We found that other limits obtained from various arguments and observations in other energy ranges either are unbinding or allow a similar maximum luminosity of the order of $\approx$$10^{35}$ erg s$^{-1}$. We conclude that while a pulsar alike the one in the Crab Nebula in both luminosity and spectrum is hardly compatible with the observations, there is ample space for an `ordinary' X-ray-emitting young neutron star, born with normal initial spin period, temperature and magnetic field, to be hiding inside the evolving remnant of SN 1987A.
翻译:超新星(SN) 1987A 的恒星前体质量和爆炸时观察到的中子粒子爆裂与中子恒星的核心折叠形成相一致。然而,在电磁频谱的任何波段中,尚未发现任何类型的紧凑物体在SN 1987A 的出现有令人信服的证据,从而引发关于中子恒星是否存活以及如果存在的话,其特性的疑问。从对钱德拉最近观测结果的分析开始,我们评估了当前的观测情况。我们从一个非热的紧凑物体的X射线光亮度中得出了与中子恒星核心的非热量、螃蟹-普尔萨相似的光线谱。在SNNA 1987A 中, 中子恒星恒星恒星的旋转能量损失限度为美元(0.5美元-1.5美元) 和当前观测情况10美元,而其他恒星系的恒星系 也有可能被排除。