PhysicsarXiv
Ranked by formulaVerdict: NotableProbing the Faint Outskirts of Star-Forming Galaxies with 1<z<9 Using Stacked Images
We present a systematic study of the faint outer light profiles of star-forming galaxies using deep JWST/NIRCam imaging from the CEERS, JADES, and PRIMER surveys.
VerdictWorth a reader's time today.
Abstract
We present a systematic study of the faint outer light profiles of star-forming galaxies using deep JWST/NIRCam imaging from the CEERS, JADES, and PRIMER surveys. Our sample consists of 14,812 face-on disk galaxies at 1<z<9 with log(M_*/M_odot)>8.5, selected from the DAWN JWST Archive. To characterize the low-surface-brightness outskirts beyond the effective radius (R_e), we stack galaxies in bins of stellar mass and redshift, accounting for cosmological surface-brightness dimming, angular-size scaling, and PSF convolution, and estimate residual backgrounds from blank-sky stacks. The color profiles generally become bluer toward larger radii, indicating negative color gradients and supporting an inside-out growth scenario. Galaxies with log(M_*/M_odot) < 9.5 at z>2.5 exhibit a weak reversal in their outermost regions, suggesting more complex stellar population gradients at early times. The outer light profiles generally exhibit a good exponential decline with radius, and the outer scale lengths measured beyond 2R_e show mass and redshift dependences remarkably similar to those of the conventional mass-size relation. This similarity suggests that the extended outer light is closely linked to the same processes governing the growth of the inner galaxy, rather than providing a direct tracer of ex-situ stellar components in the early universe. We also find little wavelength dependence in the outer scale lengths, indicating that dust attenuation likely has a limited impact at these radii. These results provide new constraints on the buildup of extended stellar distributions during cosmic noon and at earlier epochs.
The editor's rubric
- Leverage3 / 5
- A method or resource many groups across the field will adopt within a year.
- Magnitude2 / 5
- Solid incremental gain on a meaningful problem.
- Evidence3 / 5
- Solid: multiple benchmarks or cohorts, ablations, fair baselines, released code or data.
- Novelty3 / 5
- A genuinely new approach to an open problem.
- Trajectory2 / 5
- Some room to improve with obvious engineering.
- Stakes2 / 5
- Benefits a professional community (practitioners, clinicians, engineers).
Editor’s rationale
Heuristic triage from title and abstract text only, not a reading of the paper. Cues found: method (we propose); novelty (alternative to status quo); verification (error bars); scale (scalable).
How the score was computed
Desks place stronger verdicts first, then use this score to order work within the same verdict.
- Merit
- 5.2 / 10
- Adjusted merit
- 4.5 / 10
- Attention
- 0%
- Freshness
- 92%