EIGER. VI. The Correlation Function, Host Halo Mass, and Duty Cycle of Luminous Quasars at z ≳ 6

Eilers, Anna-Christina; Mackenzie, Ruari; Pizzati, Elia; Matthee, Jorryt; Hennawi, Joseph F.; Zhang, Haowen; Bordoloi, Rongmon; Kashino, Daichi; Lilly, Simon J.; Naidu, Rohan P.; Simcoe, Robert A.; Yue, Minghao; Frenk, Carlos S.; Helly, John C.; Schaller, Matthieu; Schaye, Joop

Abstract

We expect luminous (M 1450 ≲ −26.5) high-redshift quasars to trace the highest-density peaks in the early Universe. Here, we present observations of four z ≳ 6 quasar fields using JWST/NIRCam in the imaging and wide-field slitless spectroscopy mode and report a wide range in the number of detected [O iii]-emitting galaxies in the quasars’ environments, ranging between a density enhancement of δ ≈ 65 within a 2 cMpc radius—one of the largest protoclusters during the Epoch of Reionization discovered to date—to a density contrast consistent with zero, indicating the presence of a UV-luminous quasar in a region comparable to the average density of the Universe. By measuring the two-point cross-correlation function of quasars and their surrounding galaxies, as well as the galaxy autocorrelation function, we infer a correlation length of quasars at 〈z〉 = 6.25 of r0QQ=22.0−2.9+3.0cMpch−1 , while we obtain a correlation length of the [O iii]-emitting galaxies of r0GG=4.1±0.3cMpch−1 . By comparing the correlation functions to dark-matter-only simulations we estimate the minimum mass of the quasars’ host dark matter halos to be log10(Mhalo, min/M⊙)=12.43−0.15+0.13 (and log10(Mhalo, min[OIII]/M⊙)=10.56−0.03+0.05 for the [O iii] emitters), indicating that (a) luminous quasars do not necessarily reside within the most overdense regions in the early Universe, and that (b) the UV-luminous duty cycle of quasar activity at these redshifts is f duty ≪ 1. Such short quasar activity timescales challenge our understanding of early supermassive black hole growth and provide evidence for highly dust-obscured growth phases or episodic, radiatively inefficient accretion rates.

Citation

Eilers, A.-C., Mackenzie, R., Pizzati, E., Matthee, J., Hennawi, J. F., Zhang, H., Bordoloi, R., Kashino, D., Lilly, S. J., Naidu, R. P., Simcoe, R. A., Yue, M., Frenk, C. S., Helly, J. C., Schaller, M., & Schaye, J. (2024). EIGER. VI. The Correlation Function, Host Halo Mass, and Duty Cycle of Luminous Quasars at z ≳ 6. The Astrophysical Journal, 974(2), Article 275. https://doi.org/10.3847/1538-4357/ad778b

• Journal Article Type: Article
• Acceptance Date: Sep 3, 2024
• Online Publication Date: Oct 17, 2024
• Publication Date: Oct 20, 2024
• Deposit Date: Oct 25, 2024
• Publicly Available Date: Oct 25, 2024
• Journal: The Astrophysical Journal
• Electronic ISSN: 1538-4357
• Peer Reviewed: Peer Reviewed
• Volume: 974
• Issue: 2
• Article Number: 275
• DOI: https://doi.org/10.3847/1538-4357/ad778b
• Keywords: Astrostatistics techniques, Supermassive black holes, Galaxy dark matter halos, High-redshift galaxy clusters, Quasars, Large-scale structure of the universe, Clustering
• Public URL: https://durham-repository.worktribe.com/output/2977562