The most massive galaxies in the Universe stopped forming stars due to the time-integrated feedback from central supermassive black holes (SMBHs). However, the exact quenching mechanism is not yet understood, because local massive galaxies were quenched billions of years ago. Here we present JWST/NIRSpec integral-field spectroscopy observations of GS-10578, a massive, quiescent galaxy at redshift z = 3.064 ± 0.002. From its spectrum, we measure a stellar mass M_⋆ = 1.6 ± 0.2 × 10¹¹ M_⊙ and a dynamical mass M_dyn = 2.0 ± 0.5 × 10¹¹ M_⊙. Half of its stellar mass formed at z = 3.7–4.6, and the system is now quiescent, with a current star-formation rate of less than 19 M_⊙ yr⁻¹. We detect ionized- and neutral-gas outflows traced by [O iii] emission and Na i absorption, with mass outflow rates 0.14–2.9 and 30–100 M_⊙ yr⁻¹, respectively. Outflow velocities reach v_out ≈ 1,000 km s⁻¹, comparable to the galaxy escape velocity. GS-10578 hosts an active galactic nucleus, evidence that these outflows are due to SMBH feedback. The neutral outflow rate is higher than the star-formation rate. Hence, this is direct evidence for ejective SMBH feedback, with a mass loading capable of interrupting star formation by rapidly removing its fuel. Stellar kinematics show ordered rotation, with spin parameter \({\lambda }_{{{{R}}}_{{\rm{e}}}}=0.62\pm 0.07\), meaning GS-10578 is rotation-supported. This study presents direct evidence for ejective active galactic nucleus feedback in a massive, recently quenched galaxy, thus helping to clarify how SMBHs quench their hosts. The high value of \({\lambda }_{{{{R}}}_{{\rm{e}}}}\) implies that quenching can occur without destroying the stellar disk.

由于中央超大质量黑洞（SMBH）的时间积分反馈，宇宙中质量最大的星系停止形成恒星。然而，确切的猝灭机制尚不清楚，因为局部大质量星系在数十亿年前就被猝灭了。在这里，我们展示了对 GS-10578 的 JWST/NIRSpec 积分场光谱观测，GS-10578 是一个红移 z = 3.064 ± 0.002 的巨大静止星系。从它的光谱中，我们测量出恒星质量M _⋆ = 1.6 ± 0.2 × 10 ¹¹ M _⊙和动力学质量M _dyn = 2.0 ± 0.5 × 10 ¹¹ M _⊙ 。其恒星质量的一半在z = 3.7–4.6 时形成，该系统现在处于静止状态，当前的恒星形成速率小于 19 M _⊙ yr ^-1 。我们检测到通过[O iii ]发射和Na i吸收追踪的电离气体和中性气体流出，质量流出速率分别为0.14–2.9和30–100 M _⊙ yr ^-1 。流出速度达到v _out ≈ 1,000 km s ^-1 ，与星系逃逸速度相当。 GS-10578 拥有一个活跃的星系核，证据表明这些流出是由于SMBH反馈造成的。中性流出速率高于恒星形成速率。因此，这是喷射SMBH反馈的直接证据，其质量负载能够通过快速去除其燃料来中断恒星的形成。恒星运动学显示有序旋转，自旋参数\({\lambda }_{{{{R}}}_{{\rm{e}}}}=0.62\pm 0.07\) ，意味着 GS-10578 是旋转 -支持。 这项研究提供了在最近淬灭的巨大星系中喷射活动星系核反馈的直接证据，从而有助于阐明超大质量黑洞如何淬灭其宿主。 \({\lambda }_{{{{R}}}_{{\rm{e}}}}\)的高值意味着猝灭可以在不破坏恒星盘的情况下发生。