论文标题
锚定在阴影中：将天体参考框架直接绑定到黑洞事件视野
Anchored in Shadows: Tying the Celestial Reference Frame Directly to Black Hole Event Horizons
论文作者
论文摘要
无线电国际天体参考框架（ICRF）和光学GAIA CELESTIAL参考框架（GAIA-CRF2）均来自对主动银河系核和数量的超级黑孔（SMBH）产生的JET的观察。这些喷气机固有地发生变化，并且在不同的观察频率下会出现不同的情况，从而导致所得的天体参考帧（CRF）的不稳定性和系统错误。最近，事件地平线望远镜（EHT）是一种非常长的基线干涉法（VLBI）阵列，在1.3 mm处观察到M87中SMBH的直径为40 micro-As直径，表明发射区域小于黑孔阴影。使用这些SMBH“发射环”（以及相关的光子环）作为星体参考，将使所得的CRF直接固定在SMBH阴影中；可预见的未来任何CRF的最终参考点。专门用于观察SMBH事件视野的合适的空间VLBI任务可能会导致相对较大的将来的ICRF的准确性和稳定性提高两倍的范围。
Both the radio International Celestial Reference Frame (ICRF) and the optical Gaia Celestial Reference Frame (Gaia-CRF2) are derived from observations of jets produced by the Super Massive Black Holes (SMBH) powering active galactic nuclei and quasars. These jets are inherently subject to change and will appear different at different observing frequencies, leading to instabilities and systematic errors in the resulting Celestial Reference Frames (CRFs). Recently, the Event Horizon Telescope (EHT), a mm-wave Very Long Baseline Interferometry (VLBI) array, has observed the 40 micro-as diameter shadow of the SMBH in M87 at 1.3 mm, showing that the emitting region is smaller than the black-hole shadow. Use of these SMBH "emission rings" (and the associated photon rings) as astrometric references will enable the resulting CRF to be anchored directly in SMBH shadows; the ultimate reference points for any CRF for the forseeable future. A properly equipped space VLBI mission devoted to the observation of SMBH event horizons could lead to a two-orders-of-magnitude improvement in the accuracy and stabilty of the ICRF in the relatively near future.
