Supermassive black holes may suppress star formation in nearby galaxies.

JWST observations of a z = 6.3 quasar show reduced [O iii] emission in neighbouring galaxies, which the study reports as evidence that intense quasar UV radiation suppresses recent star formation across intergalactic distances.

Astronomers report that JWST observations of a very luminous quasar at redshift 6.3 are associated with reduced nebular emission in nearby galaxies. The work compares doubly-ionized oxygen ([O iii]) emission with the ultraviolet continuum in those neighbouring systems. The [O iii] emission falls nearer the quasar while the UV continuum remains similar, which the authors report as evidence of radiative suppression of recent star formation. The study is published in The Astrophysical Journal Letters and led by Yongda Zhu. Key findings: - JWST imaged the hyperluminous quasar SDSS J0100+2802 at z = 6.3 and several neighbouring galaxies. - The strength of the [O iii] λ5008 emission decreases closer to the quasar while the UV continuum of the galaxies does not show the same decline. - The authors report this pattern as consistent with intense quasar UV radiation ionizing star-forming gas and suppressing recent star formation across intergalactic scales (on the order of a million light-years). - The paper is titled "Quasar Radiative Feedback May Suppress Galaxy Growth on Intergalactic Scales at z = 6.3" and names Yongda Zhu as lead author. - The result currently rests on a single quasar and related galaxies, so broader confirmation is required. Summary: If confirmed in other systems, radiative feedback from very luminous quasars could influence how galaxies grew during the Epoch of Reionization. The authors propose further JWST wide-field NIRCam imaging and NIRSpec follow-up to test whether the same effect appears around additional early quasars.