5 papers
Constraining the nature of active galactic nuclei through circumgalactic Lya emission at z=2-3
Shiwu Zhang, Zheng Cai, Fabrizio Arrigoni Battaia +8
We present a comprehensive analysis of circumgalactic Lya nebulae around 59 unobscured and 26 obscured quasars at z=2-3, observed with the Keck Cosmic Web Imager (KCWI), to constra…
The Discovery of Little Red Dots in the Local Universe: Signatures of Cool Gas Envelopes
Xiaojing Lin, Xiaohui Fan, Zheng Cai +25
JWST observations have revealed a population of high-redshift "little red dots" (LRDs) that challenge conventional AGN models. We report the discovery of three local LRDs at $z = 0…
A Metal-Free Galaxy at ? Evidence of Late Population III Star Formation at Cosmic Noon
Sijia Cai, Mingyu Li, Zheng Cai +10
Star formation from metal-free gas, the hallmark of the first generation of Population III stars, was long assumed to occur only in the very early Universe. We report the discovery…
Luminous Mid-IR Selected Obscured Quasars at Cosmic Noon in SDSS Stripe82 II: Spectroscopic Diversity and Broad H Emissions
Ben Wang, Yuzo Ishikawa, Joseph F. Hennawi +5
We present a multiwavelength spectroscopic survey of 23 luminous mid-infrared-selected Type-2 quasars at redshifts z = 0.88 to 3.49. The targets were selected in the SDSS Stripe 82…
Luminous Mid-IR Selected Type-2 Quasars at Cosmic Noon in SDSS Stripe82 I: Selection, Composite Photometry, and Spectral Energy Distributions
Ben Wang, Joseph F. Hennawi, Zheng Cai +6
We analyze 23 spectroscopically confirmed Type-2 quasars (QSOs) selected from the WISE 22m band in the SDSS Stripe 82 region, focusing on their multi-band photometry and sp…