XRISM协作组近期研究了从类星体以相对论速度射出的结构电离风。这一研究成果于2025年5月14日发表在《自然》杂志上。

有证据表明，超大质量黑洞（SMBH）存在于大多数星系的中心。它们的质量与星系凸起的质量相关，这表明它们与宿主星系共同进化，最有可能是通过强风。X射线观测发现，高电离风以亚相对论速度从SMBH周围的吸积盘流出。然而，目前X射线仪器的有限光谱分辨率使得人们对风的物理结构和位置知之甚少，阻碍了对其动能的准确估计。 

这是对发光类星体PDS 456 的首次X射线成像和光谱学任务（XRISM）观测。XRISM上的高分辨率光谱仪Resolve能够发现以20-30%光速流出的五个离散速度分量。这表明风的结构是高度不均匀的，可能由多达一百万个团块组成。质量外流率估计为每年60-300个太阳质量，风的动能超过了爱丁顿的光度限制。与星系尺度的外流相比，动能要大三个数量级以上，而动量通量要大十倍。 

这些估计不利于能量驱动和动量驱动的外流模型。这表明，这种风活动发生在类星体阶段的不到10%的时间里，和/或由于风和星际介质的结块，其能量/动量没有有效地转移到星系规模的外流中。

附：英文原文

Title: Structured ionized winds shooting out from a quasar at relativistic speeds

Author: Ehud Behar, Kouichi Hagino, Misaki Mizumoto or James Reeves.

Issue&Volume: 2025-05-14

Abstract: Evidence indicates that supermassive black holes (SMBHs) exist at the centres of most galaxies. Their mass correlates with the galactic bulge mass1, suggesting a coevolution with their host galaxies2, most likely through powerful winds3. X-ray observations have detected highly ionized winds outflowing at sub-relativistic speeds from the accretion disks around SMBHs4,5. However, the limited spectral resolution of present X-ray instruments has left the physical structure and location of the winds poorly understood, hindering accurate estimates of their kinetic power6,7. Here the first X-Ray Imaging and Spectroscopy Mission (XRISM) observation of the luminous quasar PDS456 is reported. The high-resolution spectrometer Resolve aboard XRISM enabled the discovery of five discrete velocity components outflowing at 20–30% of the speed of light. This demonstrates that the wind structure is highly inhomogeneous, which probably consists of up to a million clumps. The mass outflow rate is estimated to be 60–300 solar masses per year, with the wind kinetic power exceeding the Eddington luminosity limit. Compared with the galaxy-scale outflows, the kinetic power is more than three orders of magnitude larger, whereas the momentum flux is ten times larger. These estimates disfavour both energy-driven and momentum-driven outflow models. This suggests that such wind activity occurs in less than 10% of the quasar phase and/or that its energy/momentum is not efficiently transferred to the galaxy-scale outflows owing to the clumpiness of the wind and the interstellar medium.

DOI: 10.1038/s41586-025-08968-2

Source: https://www.nature.com/articles/s41586-025-08968-2