3 papers
astro-ph.GA2025
Probing the \ion{He}{2} re-Ionization ERa via Absorbing \ion{C}{4} Historical Yield (HIERACHY) IV: A complex redshifted absorption system intrinsic to quasar
Huiyang Mao, Jiang-Tao Li, Xiaodi Yu +3
High-resolution spectra provide a powerful tool in studying the associated absorption lines (AALs) in quasars. We present a case study of the quasar J014741-030247 at 4.75…
astro-ph.GA2025
Probing the He II reionization ERa via Absorbing C IV Historical Yield (HIERACHY) III: The C IV absorber catalog and initial results on cosmic abundance evolution at
Xiaodi Yu, Zhijie Qu, Zheng Cai +3
As part of the HIERACHY program, we collect the high-SN and high-spectral resolution optical spectra of 25 quasars at to constrain the C IV evolution at $z\approx 3-5…
astro-ph.GA2024
Probing the He II re-Ionization ERa via Absorbing C IV Historical Yield (HIERACHY) II: Project Design, Current Status, and Examples of Initial Data Products
Jiang-Tao Li, Xiaodi Yu, Huiyang Mao +22
The He II reionization epoch is expected to take place at . In this stage, the helium and metals in the inter-galactic medium (IGM) are further ionized with additional co…