2026-04-17T23:14:13Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/2182582025-12-05T16:10:03Zcom_2072_1057col_2072_478904col_2072_478917

00925njm 22002777a 4500 dc Takahashi, A. author Matsuoka, Y. author Onoue, M. author Strauss, M. A. author Kashikawa, N. author Toba, Y. author Iwasawa, Kazushi author Imanishi, M. author Akiyama, M. author Kawaguchi, T. author Noboriguchi, A. author Lee, C.-H. author 2025-01-30T17:14:27Z 2025-01-30T17:14:27Z 2024 2025-01-30T17:14:27Z We report the distribution of black hole (BH) masses and Eddingont ratios estimated for a sample of 131 low luminosity quasars in the early cosmic epoch (5.6 < z < 7.0). Our work is based on the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project, which has constructed a low luminosity quasar sample down to M1450 ∼ − 21 mag, exploiting the survey data of Hyper Suprime-Cam installed on Subaru Telescope. The discovery spectra of these quasars are limited to the rest-frame wavelengths of ∼1200–1400 Å, which contain no emission lines that can be used as BH mass estimators. In order to overcome this problem, we made use of low-z counterpart spectra from the Sloan Digital Sky Survey, which are spectrally matched to the high-z spectra in overlapping wavelengths. We then combined the C iv emission line widths of the counterparts with the continuum luminosity from the SHELLQs data to estimate BH masses. The resulting BH mass distribution has a range of ∼107–10M⊙, with most of the quasars having BH masses ∼108M⊙ with sub-Eddington accretion. The present study provides not only a new insight into normal quasars in the reionization epoch, but also a new promising way to estimate BH masses of high-z quasars without near-infrared spectroscopy. Forats negres (Astronomia) Galàxies Quàsars Black holes (Astronomy) Galaxies Quasars Subaru High-z Exploration of Low-luminosity Quasars (SHELLQs). XVII. Black Hole Mass Distribution at z 6 Estimated via Spectral Comparison with Low-z Quasars