Skyfire: A Spectroscopic Census of Little Red Dots and Broad-Line AGN in the CEERS Field

Dale D. Kocevski, Anthony J. Taylor, Masafusa Onoue, Kohei Inayoshi, Steven L. Finkelstein, Guillermo Barro, Jingsong Guo, Pablo Arrabal Haro, Jonathan R. Trump, Rebecca L. Larson, Mark Dickinson, Casey Papovich, Fabio Pacucci, Pablo G. Perez-Gonzalez, Michaela Hirschmann, Elizabeth J. McGrath, Brenda L. Jones, Nikko J. Cleri, Kelcey Davis, Mauro Giavalisco, Norman A. Grogin, Taylor A. Hutchison, Jeyhan S. Kartaltepe, Allison Kirkpatrick, Gene C. K. Leung, Rachel S. Somerville, Stephen M. Wilkins

First listed 2026-09-02 | Last updated 2026-09-02

Abstract

Short digest

Skyfire uses 21 hours of JWST/NIRSpec G395M spectroscopy across five CEERS pointings to build a systematic census of compact broad-line AGN candidates spanning red LRDs, blue extreme-emission-line galaxies, and X-ray AGN. Among 178 measured redshifts, the program identifies 34 broad-line sources at 2.7 < z < 6.5, including 18 LRDs, raising the spectroscopic completeness of CEERS LRDs with βopt > −0.02 to 73%. Broad-line incidence stays high beyond the canonical red LRD cuts and continues into the Little Blue Dot regime, favoring a continuous LRD–LBD population; with a revised βopt ≥ −0.52 selection, 80.9% of F444W < 26.5 candidates are broad-line emitters, whereas only 3 of 17 compact high-EW EELGs show broad lines.

Key figures to inspect

• Figure 5. This is the paper’s central selection-space diagnostic: broad-line detections remain common below the canonical red optical-slope and color cuts, visually connecting LRDs to the bluer LBD regime and motivating the expanded LRD definition.
• Figure 6. This figure quantifies both spectroscopic completeness and broad-line yield across optical slope, color, and F444W magnitude, directly supporting the revised βopt threshold and the reported high efficiency of photometric LRD selection.
• Figure 7. The continuum-slope distributions show the population-level structure of CEERS broad-line emitters, including the bimodality between red LRDs and the bluest broad-line sources and the minimum near the proposed dividing slope.
• Figure 8. This redshift-dependent census places the LRD–LBD connection in evolutionary context by showing that blue non-LRD broad-line sources become increasingly important toward lower redshift and eventually dominate the broad-line population.