Xiaohui Fan

Can Blue UV-Bright Galaxies Drive Reionization at Cosmic Dawn? An $M_{UV} = - 19.6$ Galaxy with $f_{esc} \approx 0.85$ at $z = 9.244$

Yunjing Wu, Sijia Cai, Yongda Zhu +28

We revisit EBG-1, a gravitationally lensed galaxy at $z = 9.244$ , using newly obtained deep (14 hr) JWST/NIRSpec G235M ( $R \sim 1000$ ) spectroscopy. EBG-1 is one of the bluest gala…

Calcium Triplet Absorption is Common around Little Red Dots

Jenny E. Greene, Hanpu Liu, Raphael E. Hviding +29

We present new evidence for an optically thick atmosphere surrounding Little Red Dots (LRDs) in the form of Ca absorption at rest-frame 8500A, the calcium triplet (CaT). Building o…

LATED: JWST integral field spectroscopy of a galaxy caught in chemical infancy at $z = 4.8$ behind Abell 2744

Mingyu Li, Roberto Maiolino, Zheng Cai +26

When Population III (Pop III) star formation ended remains an open question. LATED-1 is an intrinsically faint ( $M_{UV} = - 16.15$ ) Ly $α$ emitter at $z = 4.80$ revealed by VLT/MU…

LATED: Ly $α$ -anchored photometric selection of candidate metal-free and extremely metal-poor star formation from the end of reionisation to cosmic noon

Mingyu Li, Zheng Cai, Roberto Maiolino +24

Cosmological simulations allow a low-level tail of Population III (Pop III) star formation to persist to $z = 2 - 6$ . Spectroscopic confirmation is expensive, so an efficient photometr…

The Roman eXtreme Deep Field (RXDF)

Haojing Yan, Anton M. Koekemoer, Yue Shen +127

The Roman eXtreme Deep Field (RXDF) program is one of the five General Astrophysics Survey (GAS) programs approved for observing time with the Nancy Grace Roman Space Telescope in…

Low Ly $α$ Visibility in Galaxy Overdensities: Reionization Topology and Neutral-Fraction Ceilings from DIVER over $4.8 < z < 11$

Yongda Zhu, Xiaohui Fan, Laura C. Keating +19

Ly-alpha emission is widely used to trace cosmic reionization, but its interpretation depends on how Ly-alpha visibility varies with galaxy environment. We use deep JWST/NIRSpec ob…

Misaligned or chaotic? A strong break of axial symmetry in the local LRD J1025 revealed with VLT/FORS2 spectropolarimetry

Francesco D'Eugenio, Gabriele Pezzulli, Roberto Maiolino +18

Little Red Dots (LRDs) are compact active galactic nuclei (AGN) with unusual spectral energy distributions and broad Balmer emission, candidate signposts of rapid black-hole growth…

A quasar hatching from a buried red phase at z = 3.7

Zheng Ma, Yongda Zhu, Zhiyuan Ji +21

We present JADES-GS 209777, previously cataloged as CANDELS J033238.02-274626.2, hereafter "the Hatchling," a red quasar at $z = 3.711$ . While the source has been reported in earlier…

The MIRI Early Obscured-AGN Wide Survey (MEOW): A Population of Hidden AGN at $z ≳ 5$ Revealed by JWST/MIRI Imaging

Gene C. K. Leung, Anna-Christina Eilers, Ryan Endsley +25

We present the MIRI Early Obscured-AGN Wide Survey (MEOW), a JWST/MIRI imaging survey designed to detect dust-obscured active galactic nuclei (AGN) across cosmic time, with a parti…

A Post-starburst Galaxy Undergoing Ram-pressure Stripping at Redshift 3.06

Mingyu Li, Zheng Cai, Bjorn H. C. Emonts +16

Understanding how galaxies ignite and extinguish their star formation remains a cornerstone question in modern astrophysics. Recent JWST surveys have revealed an overabundance of m…

Little red dot variability over a century reveals black hole envelope via a giant Einstein cross

Zijian Zhang, Mingyu Li, Masamune Oguri +79

"Little red dots" (LRDs) represent a new population of astronomical objects uncovered by JWST whose nature remains debated. Although many LRDs are suspected as active galactic nucl…

astro-ph.HE2025

A Deep Chandra X-ray Survey of a Luminous Quasar Sample at $z \sim$ 7

Xiangyu Jin, Feige Wang, Jinyi Yang +11

We present new Chandra observations of seven luminous quasars at $z > 6.5$ . Combined with archival Chandra observations of all other known quasars, they form nearly complete X-ray ob…

COSMOS-3D: Dense Circumnuclear Gas across Black Hole Growth Phases at z ~ 3

Zi-Jian Li, Siwei Zou, Jianwei Lyu +25

We report the discovery of two broad-line X-ray AGNs (cid_414 and cid_947) at z ~ 3 identified in the JWST Cycle 3 COSMOS-3D program using NIRCam F444W grism spectroscopy. Both exh…

A JWST/NIRSpec Integral Field Unit Survey of Luminous Quasars at z ~ 5-6 (Q-IFU): Rest-frame Optical Nuclear Properties and Extended Nebulae

Weizhe Liu, Xiaohui Fan, Richard Green +10

It remains debatable how billion-solar-mass supermassive black holes (SMBHs) form and evolve within the first billion years. We report results from a James Webb Space Telescope (JW…

Quasar Radiative Feedback May Suppress Galaxy Growth on Intergalactic Scales at $z = 6.3$

Yongda Zhu, Eiichi Egami, Xiaohui Fan +27

We present observational evidence that intense ionizing radiation from a luminous quasar suppresses nebular emission in nearby galaxies on intergalactic scales at $z = 6.3$ . Using JW…

astro-ph.CO2025

First constraints on the local ionization topology in front of two quasars at z ~ 7.5

Timo Kist, Joseph F. Hennawi, Frederick B. Davies +10

Thus far, Lyman- $α$ damping wings towards quasars have been used to probe the \textit{global} ionization state of the foreground intergalactic medium (IGM). A new parameterization…

AGNs in the extremely overdense galaxy region BOSS 1441: A Chandra observation

Jiahua Wu, Liming Dou, Zheng Cai +6

We present a Chandra/ACIS-I study of X-ray sources in BOSS 1441, a protocluster at $z = 2.32 \pm 0.02$ that exhibits a prominent overdensity of Ly $α$ emitters (LAEs). Using a 45 ks obs…

The Identification of Two JWST/NIRCam-Dark Starburst Galaxies at $z = 6.6$ with ALMA

Fengwu Sun, Jinyi Yang, Feige Wang +20

We analyze two dusty star-forming galaxies at $z = 6.6$ . These galaxies are selected from the ASPIRE survey, a JWST Cycle-1 medium and ALMA Cycle-9 large program targeting 25 quasars…

astro-ph.GA2025★ 4 cited

SAPPHIRES: Extremely Metal-Poor Galaxy Candidates with $12 + log (O/H) < 7.0$ at $z \sim 5 - 7$ from Deep JWST/NIRCam Grism Observations

Tiger Yu-Yang Hsiao, Fengwu Sun, Xiaojing Lin +19

Population III stars, the hypothetical first generation metal-free stars, have yet to be discovered. Even after three years of successful JWST operations, studies have shown that m…

The Large-scale Environments of Low-luminosity AGNs at $3.9 < z < 6$ and Implications for Their Host Dark Matter Halos from a Complete NIRCam Grism Redshift Survey

Xiaojing Lin, Xiaohui Fan, Fengwu Sun +19

We study the large-scale environments and clustering properties of 28 low-luminosity AGNs at $z = 3.9 - 6$ in the GOODS-N field. Our sample, identified from the JWST NIRCam Imaging and…

astro-ph.GA2025★ 2 cited

Counting Little Red Dots at $z < 4$ with Ground-based Surveys and Spectroscopic Follow-up

Yilun Ma, Jenny E. Greene, David J. Setton +13

Little red dots (LRDs) are a population of red, compact objects discovered by JWST at $z > 4$ . At $4 < z < 8$ , they are roughly 100 times more abundant than UV-selected quasars. However,…

astro-ph.GA2025★ 2 cited

Bridging Quasars and Little Red Dots: Insights into Broad-Line AGNs at $z = 5 - 8$ from the First JWST COSMOS-3D Dataset

Xiaojing Lin, Xiaohui Fan, Feige Wang +30

We report the discovery of 13 broad-line AGNs at $z = 5 - 8$ from the first 10% data of the JWST Cycle 3 Treasury Program COSMOS-3D. These AGNs are identified by their broad H $α$ o…