A5114514273- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Galaxies: Formation, Evolution, Phenomena
- Solar and Space Plasma Dynamics
Peking University
2024
Kavli Institute for Theoretical Sciences
2024
Cosmic reionization represents the latest phase transition of intergalactic medium (IGM) in Universe. It has long been debated whether galaxies or active galactic nuclei (AGNs) are major source Lyman continuum (LyC) photons responsible for reionization. Previous observations slightly favored as ionizing source. However, James Webb Space Telescope (JWST) recently discovered an unexpectedly high density AGN candidates at redshift, which largely enhanced influence AGNs. Here we derive a...
Abstract The Fe ii /Mg emission line flux ratio in quasar spectra serves as a proxy for the relative to α -element abundances broad-line regions of quasars. Due expected different enrichment timescales two elements, they can be used cosmic clock early Universe. We present study ratios sample luminous quasars exploiting high-quality near-IR taken primarily by XQR-30 program with VLT XSHOOTER. These have median bolometric luminosity log( L bol [erg s −1 ]) ∼ 47.3 and cover redshift range z =...
The Fe II/Mg II emission line flux ratio in quasar spectra serves as a proxy for the relative to alpha-element abundances broad regions of quasars. Due expected different enrichment timescales two elements, they can be used cosmic clock early Universe. We present study ratios sample luminous quasars exploiting high-quality near-IR taken primarily by XQR-30 program with VLT XSHOOTER. These have median bolometric luminosity log(L_bol[erg s^-1])~47.3 and cover redshift range z=6.0-6.6. value...