activity
20202026
most citedObservability of Low-Luminosity AGN in the Early Universe with JWST

29 citations · 58 across the 14 of their papers we have counts for

collaborators

14 papers

astro-ph.GA2026

Early Supermassive Black Holes and Little Red Dots Require Free-Fall Growth

Junehyoung Jeon, Volker Bromm, Michael Boylan-Kolchin +1

Supermassive black holes/active galactic nuclei (SMBHs/AGN), forming only a few hundred million years after the Big Bang as observed with the James Webb Space Telescope (JWST), cha…

astro-ph.GA2026

The Road to Normalcy: Environment-Driven Evolutionary Pathways for Primordial Black Holes

Saiyang Zhang, Junehyoung Jeon, Boyuan Liu +2

We investigate how cosmological environment regulates the evolution of primordial black hole (PBH) seeds in the early universe using a suite of hydrodynamical simulations. Unlike t…

astro-ph.GA2026

A Rapid Evolution in the Observed Mbh/M* Relation at z > 3 Revealed via Spectro-photometric SED-Modeling

Ansh R. Gupta, Anthony Taylor, Emma Curtis-Lake +33

Spectroscopic observations from JWST have uncovered a plethora of active galactic nuclei (AGN) at z > 4 with black hole (BH) mass (Mbh) to stellar mass (M*) ratios significantly ab…

astro-ph.GA2026

What is Powering the Enigmatic He II Emitter Hebe: The First Stars or Black Holes?

Junehyoung Jeon, Tae Bong Jeong, Saiyang Zhang +1

Recent high-resolution spectroscopy with the James Webb Space Telescope (JWST) has confirmed the presence of a strong He II emitting clump in the vicinity of GN-z11,…

astro-ph.GA2026

Hunting for the First Explosions at the High-Redshift Frontier

Junehyoung Jeon, Volker Bromm, Alessandra Venditti +2

The James Webb Space Telescope (JWST) has spectroscopically confirmed galaxies up to , 300 Myr after the Big Bang, and several candidates have been discovered at $z\sim15-…

astro-ph.GA2025

A GLIMPSE of Intermediate Mass Black holes in the epoch of reionization: Witnessing the Descendants of Direct Collapse?

Qinyue Fei, Seiji Fujimoto, Rohan P. Naidu +17

JWST has revealed an abundance of supermassive black holes (BHs) in the early Universe, and yet the lowest mass seed black holes that gave rise to these populations remain elusive.…

astro-ph.GA2025★ 4 cited

Little Red Dots and their Progenitors from Direct Collapse Black Holes

Junehyoung Jeon, Boyuan Liu, Volker Bromm +7

The James Webb Space Telescope (JWST) has discovered a new population of objects, the Little Red Dots (LRDs), characterized by V-shaped spectra indicative of strong breaks around t…

astro-ph.GA2025

How do Massive Primordial Black Holes Impact the Formation of the First Stars and Galaxies?

Saiyang Zhang, Boyuan Liu, Volker Bromm +3

We investigate the impact of massive primordial black holes (PBHs; ) on the star formation and first galaxy assembly process using high-resolution hy…

astro-ph.GA2025

The Emerging Black Hole Mass Function in the High-Redshift Universe

Junehyoung Jeon, Boyuan Liu, Anthony J. Taylor +5

Observations with the James Webb Space Telescope (JWST) have identified an abundant population of supermassive black holes (SMBHs) already in place during the first few hundred mil…

astro-ph.GA2024★ 10 cited

Broad-Line AGN at 3.5<z<6: The Black Hole Mass Function and a Connection with Little Red Dots

Anthony J. Taylor, Steven L. Finkelstein, Dale D. Kocevski +48

We present a sample of 50 H-alpha detected broad-line active galactic nuclei (BLAGN) at redshifts 3.5<z<6.8 using data from the CEERS and RUBIES surveys. We select these sources di…

astro-ph.GA2024★ 6 cited

Physical Pathways for JWST-Observed Supermassive Black Holes in the Early Universe

Junehyoung Jeon, Volker Bromm, Boyuan Liu +1

Observations with the James Webb Space Telescope (JWST) have revealed active galactic nuclei (AGN) powered by supermassive black holes (SMBHs) with estimated masses of …

astro-ph.GA2023★ 29 cited

Observability of Low-Luminosity AGN in the Early Universe with JWST

Junehyoung Jeon, Boyuan Liu, Volker Bromm +1

Active galactic nuclei (AGN) in the early Universe are thought to be prominent sources of energy and ionizing photons that affected the growth of their host galaxy and their enviro…

astro-ph.CO2022★ 9 cited

Maximal X-ray feedback in the pre-reionization universe

Junehyoung Jeon, Volker Bromm, Steven L. Finkelstein

X-ray feedback in the pre-reionization Universe provided one of the major energy sources for reionization and the thermal evolution of the early intergalactic medium. However, X-ra…

astro-ph.GA2020

SED Analysis of 13 Spectroscopically Confirmed Galaxies at z6 to Constrain UV-Slope, Model Dust Attenuation and Escape Fractions

Junehyoung Jeon, Rogier Windhorst, Seth H. Cohen +8

The reionization of the hydrogen in the Universe is thought to have completed by redshift . To probe this era, galaxy observations in the Subaru Deep Field (SDF) have…