ATLAS. IV. A JWST+MUSE Demographic Study of Ly$α$ Profiles in Little Red Dots

[2608.14534] ATLAS. IV. A JWST+MUSE Demographic Study of Ly$α$ Profiles in Little Red Dots Skip to main content Search Submit Donate Log in Search arXiv Press Enter to search · Advanced search Astrophysics > Astrophysics of Galaxies arXiv:2608.14534 (astro-ph) [Submitted on 14 Aug 2026] Title: ATLAS. IV. A JWST+MUSE Demographic Study of Ly$α$ Profiles in Little Red Dots Authors: Yuta Kageura , Masami Ouchi , Hiroto Yanagisawa , Makoto Ando , Yuichi Harikane , Tomokazu Kiyota , Minami Nakane , Yoshiaki Ono , Yui Takeda View a PDF of the paper titled ATLAS. IV. A JWST+MUSE Demographic Study of Ly$\alpha$ Profiles in Little Red Dots, by Yuta Kageura and 8 other authors View PDF HTML (experimental) Abstract: We present an initial demographic study of Ly$\alpha$ profiles in little red dots (LRDs) at $z=3$--9 using $R\sim1000$--4000 spectroscopy. Our sample consists of 8 LRDs observed in the VLT/MUSE Deep and Wide surveys and 23 LRDs observed with JWST/NIRSpec grating spectroscopy from JADES, CANUCS, and GO programs including SPURS. We identify Ly$\alpha$ emission in 5 MUSE LRDs and 9 JWST LRDs. Only two of them exhibit broad Ly$\alpha$ emission (FWHM $>1000\ \mathrm{km\ s^{-1}}$), both reported previously. The other Ly$\alpha$-emitting LRDs show narrow Ly$\alpha$ emission (FWHM $<1000\ \mathrm{km\ s^{-1}}$), with FWHMs mostly in the range 300--600 $\mathrm{km\ s^{-1}}$, comparable to or slightly larger than those of high-redshift star-forming galaxies (100--500 $\mathrm{km\ s^{-1}}$). We measure the fraction of broad Ly$\alpha$ emitters above a broad Ly$\alpha$ luminosity threshold of $L_{\mathrm{Ly}\alpha,\mathrm{broad}}=10^{42}\ \mathrm{erg\ s^{-1}}$, obtaining $0.10^{+0.12}_{-0.07}$ for LRDs, about five times higher than the $2\sigma$ upper limit of $<0.02$ for high-redshift star-forming galaxies. Although we reproduce the broad Ly$\alpha$ component reported in a previous stacking analysis of eight LRDs, albeit with a large uncertainty, we find no evidence for broad Ly$\alpha$ emission in either the larger JWST stack, after excluding the two individually detected broad Ly$\alpha$ emitters, or the higher-resolution MUSE stack. These results suggest that broad Ly$\alpha$ emission is not ubiquitous among LRDs. Instead, LRDs with broad Ly$\alpha$ emission appear to represent a rare population that may correspond to a particular evolutionary stage, potentially associated with unusually strong outflows or other distinctive physical conditions. Comments: 23 pages, 12 figures, submitted to ApJ Subjects: Astrophysics of Galaxies (astro-ph.GA) Cite as: arXiv:2608.14534 [astro-ph.GA] (or arXiv:2608.14534v1 [astro-ph.GA] for this version) https://doi.org/10.48550/arXiv.2608.14534 Focus to learn more arXiv-issued DOI via DataCite Submission history From: Yuta Kageura [ view email ] [v1] Fri, 14 Aug 2026 17:49:40 UTC (1,798 KB) Full-text links: Access Paper: View a PDF of the paper titled ATLAS. IV. A JWST+MUSE Demographic Study of Ly$\alpha$ Profiles in Little Red Dots, by Yuta Kageura and 8 other authors View PDF HTML (experimental) TeX Source view license Current browse context: astro-ph.GA < prev | next > new | recent | 2026-08 Change to browse by: astro-ph References & Citations NASA ADS Google Scholar Semantic Scholar export BibTeX citation Loading... BibTeX formatted citation × loading... Data provided by: Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer ( What is the Explorer? ) Connected Papers Toggle Connected Papers ( What is Connected Papers? ) Litmaps Toggle Litmaps ( What is Litmaps? ) scite.ai Toggle scite Smart Citations ( What are Smart Citations? ) Code, Data, Media Code, Data and Media Associated with this Article alphaXiv Toggle alphaXiv ( What is alphaXiv? ) Links to Code Toggle CatalyzeX Code Finder for Papers ( What is CatalyzeX? ) DagsHub Toggle DagsHub ( What is DagsHub? ) GotitPub Toggle Gotit.pub ( What is GotitPub? ) Huggingface Toggle Hugging Face ( What is Huggingface? ) ScienceCast Toggle ScienceCast ( What is ScienceCast? ) Demos Demos Replicate Toggle Replicate ( What is Replicate? ) Spaces Toggle Hugging Face Spaces ( What is Spaces? ) Spaces Toggle TXYZ.AI ( What is TXYZ.AI? ) Related Papers Recommenders and Search Tools Link to Influence Flower Influence Flower ( What are Influence Flowers? ) Core recommender toggle CORE Recommender ( What is CORE? ) IArxiv recommender toggle IArxiv Recommender ( What is IArxiv? ) Author Venue Institution Topic About arXivLabs arXivLabs: experimental projects with community collaborators arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website. Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them. Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs . Which authors of this paper are endorsers? | Disable MathJax ( What is MathJax? ) We gratefully acknowledge support from our major funders , member institutions , , and all contributors. About · Help · Contact · Subscribe · Copyright · Privacy · Accessibility · Operational Status (opens in new tab) Major funding support from

Related documents

• Herbarium-based measurements are reliable predictors of fresh plant traits in Neotropical Myrtaceae.#975577
• Above- and Belowground Traits are Linked Within Species, but Vary Differently Along Environmental Gradients.#425508
• NO-GAP: Student-Level Data: Cohort of 8th-Grade Students of the School Year 2021-2022#461116
• <b>N</b><b>est-site selection and breeding success</b><b> in the g</b><b>rey bush chat: a comparison between two geographic populations</b>#357074
• FOLKNET database - Demographic Data Base#373172