Year: 2026
Type: article
Abstract: High-redshift quasars are powerful tracers of both astrophysical processes and large-scale structure in the early Universe. Using a sample of 1242 spectroscopically confirmed quasars and 827 highly reliable photometric quasar candidates selected with a machine learning framework, all at 4.7 ≤ z < 6.3 (excluding 5.4 < z < 5.6) and with a median luminosity of M 1450 ∼ −25.5, we investigate the large-scale environments of quasars near the end of cosmic reionization. We measure the projected autocorrelation function of the quasar population and derive bias parameters of b = 22.1 1 − 2.19 + 2.17 and 28.5 5 − 5.75 + 5.76 for the redshift intervals 4.7 ≤ z < 5.4 and 5.6 ≤ z < 6.3, respectively. These correspond to characteristic dark matter halo masses of log ( M h / M ⊙ ) = 12.6 6 − 0.11 + 0.10 and 12.6 2 − 0.21 + 0.21 , respectively. We further estimate quasar duty cycles of 0.01 1 − 0.007 + 0.017 and 0.01 2 − 0.011 + 0.104 for the two redshift bins. These measurements are consistent with previous studies and the observed f duty – M halo relation, indicating that only a small fraction of suitable dark matter halos host optically luminous quasars at any given time. The inferred low duty cycles suggest that a substantial fraction of supermassive black hole (SMBH) growth may occur during obscured accretion phases. Our results provide new constraints on the connection between high-redshift quasars and their host dark matter halos, offering valuable insights into the coevolution of SMBHs and large-scale structure in the early Universe.
Institution: Huazhong University of Science and Technology
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,400
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, National Natural Science Foundation of China, Consejo Nacional de Ciencia y Tecnología, Huazhong University of Science and Technology, European Southern Observatory, Ministerio de Ciencia e Innovación, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Office of Science, Science and Technology Facilities Council, Division of Astronomical Sciences, Lawrence Berkeley National Laboratory
OpenAlex ID: W7215047649