Pierluigi Rinaldi, Nina Bonaventura, G. H. Rieke, Stacey Alberts, K. I. Caputi, William Baker, Stefi A. Baum, Rachana Bhatawdekar, Andrew J. Bunker, Stefano Carniani, Emma Curtis-Lake, Francesco D’Eugenio, Eiichi Egami, Zhiyuan Ji, Benjamin D. Johnson, Kevin Hainline, Jakob M. Helton, Xiaojing Lin, Jianwei Lyu, Zheng Ma, R. Maiolino, Pablo G. Pérez‐González, Marcia Rieke, Brant Robertson, Irene Shivaei, Meredith A. Stone, Yang Sun, Sandro Tacchella, Hannah Übler, Christina C. Williams, Christopher N. A. Willmer, Chris J. Willott, Junyu Zhang, Yongda Zhu
Abstract We analyze 99 photometrically selected Little Red Dots (LRDs) at z ≈ 4–8 in the GOODS fields, leveraging ultradeep JADES NIRCam short-wavelength (SW) data. Among the 99 selected LRDs, we examine the morphology of 30. The remaining 69 appear predominantly compact, with sizes ≲400 pc and no extended components even in stacked SW images. However, their unresolved nature may partly reflect current depth limitations, which could prevent the detection of faint diffuse components. Among the 30 morphologically analyzed LRDs, 50% show multiple associated components, while the rest exhibit highly asymmetric structures, despite appearing as single sources. This diversity in rest-frame UV morphologies may point to interactions or strong internal feedback. We find median stellar masses of log 10 ( M ⋆ / M ⊙ ) = 9.0 7 − 0.08 + 0.11 for pure stellar models with A V ≈ 1.1 6 − 0.21 + 0.11 mag, and log 10 ( M ⋆ / M ⊙ ) = 9.6 7 − 0.27 + 0.17 for models including active galactic nuclei (AGNs) with A V ≈ 2.7 4 − 0.71 + 0.55 mag, in line with recent studies suggesting higher masses and dust content for AGN-fitted LRDs. NIRSpec spectra are available for 15 sources, six of which are also in the morphological sample. Broad H α is detected in 40% (FWHM = 1200–2900 km s −1 ), and one source shows broad H β emission. Emission line ratios indicate a composite nature, consistent with both AGN and stellar processes. Altogether, these results suggest that LRDs are a mixed population, and their rest-frame UV morphology reflects this complexity. Morphological studies of larger samples could provide a new way to understand what drives their properties and evolution.