A JWST/NIRSpec Integral Field Unit Survey of Luminous Quasars at z ~ 5-6 (Q-IFU): Rest-frame Optical Nuclear Properties and Extended Nebulae

TL;DR

This study uses JWST/NIRSpec to analyze 27 luminous quasars at redshifts 5-6, revealing their black hole properties, extended nebulae, and signs of galaxy interactions, shedding light on early SMBH growth and galaxy evolution.

Contribution

First systematic JWST/NIRSpec IFU survey of high-redshift quasars, providing detailed insights into their nuclear properties and surrounding nebulae at z~5-6.

Findings

SMBH masses range from 10^8.6 to 10^9.7 solar masses.

Extended [O III] emission detected in 6 quasars, indicating merging or turbulent ISM.

Evidence of quasar feedback influencing the host galaxy environment.

Abstract

It remains debatable how billion-solar-mass supermassive black holes (SMBHs) form and evolve within the first billion years. We report results from a James Webb Space Telescope (JWST)/NIRSpec integral field unit (IFU) survey of 27 luminous quasars at $z \sim 5$-$6$, enabling a systematic investigation of their key physical properties and the associated, extended line emission. Our sample hosts SMBHs with $\log(M_{\mathrm{BH}}/M_\odot) \sim 8.6$-$9.7$ and Eddington ratios of $\sim 0.1$-$2.6$ based on H$\beta$, and the H$\beta$-based and H$\alpha$-based BH mass are broadly consistent with each other. Our sample may have a slightly smaller median BH mass and larger median Eddington ratio than lower-redshift quasars within the same luminosity range, although the difference could still be explained by statistical uncertainties. They generally follow the empirical correlations between [O III] $\lambda$5007 equivalent width and bolometric luminosities or Eddington ratios formed by lower-redshift quasars. The majority of them fall within the Eigenvector~1 planes formed by lower-redshift quasars. Nevertheless, a subset of the sample shows enhanced, blueshifted [O III] emission associated with fast outflows. Spatially extended [O III] line emission is detected in 6 objects and shows morphologies and kinematics consistent with merging activities and/or turbulent and clumpy interstellar media (ISM). Tentative evidence of quasar radiative feedback shaping the ISM of a merging companion galaxy is seen in the object with the most extended [O III] emission. Our results provide crucial insight into the rapid growth of SMBHs and the gaseous environments they reside in at z$\sim$5-6.