The recently reported observation of VFTS 243 is the first example of a massive black-hole binary system with negligible binary interaction following black-hole formation. The black-hole mass ($\approx 10M_{\odot }$) and near-circular orbit ($e\approx 0.02$) of VFTS 243 suggest that the progenitor star experienced complete collapse, with energy-momentum being lost predominantly through neutrinos. VFTS 243 enables us to constrain the natal kick and neutrino-emission asymmetry during black-hole formation. At 68% confidence level, the natal kick velocity (mass decrement) is $\lesssim 10\mathrm{km}/\mathrm{s}$ ($\lesssim 1.0M_{\odot }$), with a full probability distribution that peaks when $\approx 0.3M_{\odot }$ were ejected, presumably in neutrinos, and the black hole experienced a natal kick of $4\mathrm{km}/\mathrm{s}$. The neutrino-emission asymmetry is $\lesssim 4\%$, with best fit values of $\sim 0–0.2\%$. Such a small neutrino natal kick accompanying black-hole formation is in agreement with theoretical predictions.

中文翻译：

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对来自黑洞二元 VFTS 243 的中微子纳塔尔踢的限制

最近报道的 VFTS 243 观测是第一个大质量黑洞双星系统的例子，在黑洞形成后，双星相互作用可以忽略不计。黑洞质量（$\approx 10{\mathrm{中号}}_{\odot }$）和近圆轨道（$e\approx 0.02$VFTS 243 的 ) 表明，这颗祖星经历了完全塌缩，能量动量主要通过中微子损失。 VFTS 243 使我们能够限制黑洞形成过程中的初始冲击和中微子发射不对称性。在 68% 置信水平下，出生踢速度（质量减量）为$\lesssim 10\mathrm{公里}/\mathrm{s}$（$\lesssim 1.0{\mathrm{中号}}_{\odot }$），具有完全概率分布，当$\approx 0.3{\mathrm{中号}}_{\odot }$大概是在中微子中被喷射出来，黑洞经历了一次诞生的冲击$4\mathrm{公里}/\mathrm{s}$。中微子发射不对称性为$\lesssim 4\%$，最佳拟合值为$～0–0.2\%$。伴随黑洞形成而产生的如此小的中微子出生踢与理论预测一致。