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名稱Title
2021天文年會
國立嘉義大學蘭潭校區
5月21日至23日

論文摘要

Cosmic reionization history recovered by the Subaru High-z Exploration of Low-Luminosity Quasars project

[ Oral ]

Ting-Yi Lu (NTHU), Tomotsugu Goto (NTHU), Tetsuya Hashimoto (NTHU), Daryl Joe D. Santos (NTHU), Seong Jin Kim (NTHU), Alvina Y. L. On (UCL), Yoshiki Matsuoka (Ehime U.), Toru Nagao (Ehime U.), and the SHELLQs team

The reionization history of the intergalactic medium (IGM) at z>5 is critical for us to understand the formation of first stars and galaxies. High-z quasars are one of the most powerful probes of cosmic reionization history because their high luminosities make them easy to be detected from distance. However, past studies only detected the most luminous quasars and used them to constrain the reionisation history. Limited sample size due to the small quasar population at high-luminosity end results in loose constraints on reionization parameters such as the IGM neutral fraction. In this work, to improve the constraint on the reionization history, we make use of the 93 z>6 quasars recently discovered by the Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) project. The SHELLQs quasars take half of the known quasars population at z>6 and thus could potentially place the tightest constraint on the reionization history. We present the IGM Lya photon transmission, the quasar age, and the HI background photoionization rate at z>6 measured using redshifted Lya absorptions in the UV spectra of the SHELLQs quasars. We find the IGM transmission rise rapidly at 5.5