2023/10/27 by Meredith A. Stone, Jianwei Lyu, Stone, Meredith A. +7 · 23 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #Astrophysics of Galaxies (astro-ph.GA) #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena
paper · pdf · doi:10.48550/arxiv.2310.18395
openalex publication_date 2023/10/27 · openalex created_date 2023/11/01 · openalex updated_date 2026/07/28
We measure host galaxy stellar masses for a sample of five luminous quasars at z∼5-7. Using JWST/NIRCam medium-band images of nearby PSF reference stars, we carefully subtract the contribution from the quasar light to place upper and lower limits on the flux of each host galaxy. We find that the members of our sample of quasar host galaxies have masses of 109.7 - 1010.8 M\odot, significantly less than expected from their SMBH masses and the local \magorrian relation. We additionally obtain JWST/NIRSpec IFU spectra of three of our quasars to calculate black hole masses, which we find are consistent with those in the literature, and to search for the presence of a bright but compact galaxy via a Balmer break, which we do not find evidence for. We discuss the potential effects of dust extinction on our measured fluxes and the impact of selection effects on high-redshift quasar samples. We conclude that the masses of the SMBHs relative to the host galaxy stellar masses have a much larger scatter than locally, large enough that these selection effects cannot be responsible. The result is reinforced by other studies. Finally, we explore the potential implications of these results on the picture of SMBH-galaxy coeval growth in the early Universe.