巨大ブラックホールが近傍銀河の星形成を抑制する仕組みを解明（Cosmic predators: How supermassive black holes slow star growth in nearby galaxies）

2026-02-16 アリゾナ大学

＜関連情報＞

• https://news.arizona.edu/news/cosmic-predators-how-supermassive-black-holes-slow-star-growth-nearby-galaxies
• https://iopscience.iop.org/article/10.3847/2041-8213/ae1f8e

クエーサーの放射フィードバックは、 z = 6.3における銀河間スケールでの銀河の成長を抑制する可能性がある Quasar Radiative Feedback May Suppress Galaxy Growth on Intergalactic Scales at z = 6.3

Yongda Zhu, Eiichi Egami, Xiaohui Fan, Fengwu Sun, George D. Becker, Christopher Cain, Huanqing Chen, Anna-Christina Eilers, Yoshinobu Fudamoto, Jakob M. Helton
The Astronomical Journal Letters  Published: 2025 December 3
DOI:10.3847/2041-8213/ae1f8e

Abstract

We present observational evidence that intense ionizing radiation from a luminous quasar suppresses nebular emission in nearby galaxies on intergalactic scales at z = 6.3. Using JWST/NIRCam grism spectroscopy from the Slitless Areal Pure-Parallel High-Redshift Emission survey and Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization programs, we identify a moderate but statistically significant decline in [O iii] λ5008 luminosity relative to the UV continuum (L₅₀₀₈/L₁₅₀₀) among galaxies within ∼7 comoving Mpc (cMpc) of the quasar J0100+2802, the most UV-luminous quasar known at this epoch (M₁₄₅₀ = −29.26). While L₁₅₀₀ remains roughly constant with transverse distance, L₅₀₀₈ increases significantly, suggesting suppression of very recent star formation toward the quasar. The effect persists after controlling for completeness, local density, and UV luminosity, and correlates with the projected photoionization-rate profile Γ_qso. A weaker but directionally consistent suppression in L₅₀₀₈/L₁₅₀₀ is also observed along the line of sight. The transverse suppression radius (∼7 cMpc) implies a recent radiative episode with a cumulative duration ∼3.1 Myr, shorter than required for thermal photoheating to dominate and thus more naturally explained by rapid H₂ photodissociation and related radiative processes. Environmental effects alone appear insufficient to explain the signal. Our results provide direct, geometry-based constraints on large-scale quasar radiative feedback and recent quasar lifetimes.