Pascal A. Oesch
Gabriel Brammer
Andrea Weibel
Yijia Li
Jorryt Matthee
John Chisolm
Clara L. Pollock
Kasper E. Heintz
Benjamin D. Johnson
Xuejian Shan
Raphael E. Hviding
Joel Leja
Sandro Tacchella
Arpita Ganguly
Callum Witten
Hakim Atek
Siro Belli
Sownak Bose
Rychard Bouwens
Pratika Dayal
Roberto Decarli
Anna de Graaff
Yoshinobu Fudamoto
Emma Giovinazzo
Jenny E. Greene
Garth Illingworth
Akio K. Inoue
Sarah G. Kane
Ivo Labbe
Ecaterina Leonova
Rui Marques-Chaves
Roman A. Meyer
Erica J. Nelson
Guido Roberts-Borsani
Daniel Schaerer
Robert A. Simcoe
Mauro Stefanon
Yuma Sugahara
Sune Toft
Arjen van der Wel
Pieter van Dokkum
Fabian Walter
Darrach Watson
John R. Weaver
Katherine E. Whitaker
Naidu, Rohan P., Pascal A. Oesch, Gabriel Brammer, Andrea Weibel, Yijia Li, Jorryt Matthee, John Chisolm, et al. 2026. “A Cosmic Miracle: A Remarkably Luminous Galaxy at zspec = 14.44 Confirmed with JWST.” The Open Journal of Astrophysics 9 (January). https://doi.org/10.33232/001c.156033.
JWST has revealed a stunning population of bright galaxies at surprisingly early epochs, z>10, where few such sources were expected. Here we present the most distant example of this class yet – MoM-z14, a luminous (MUV=−20.2) source in the COSMOS legacy field at zspec=14.44+0.02−0.02 that expands the observational frontier to a mere 280 million years after the Big Bang. The redshift is confirmed with NIRSpec/prism spectroscopy through a sharp Lyman-α break and ≈3σ detections of five rest-UV emission lines. The number density of bright zspec≈14−15 sources implied by our “Mirage or Miracle” survey spanning ≈350 arcmin(2 is >100× larger (182+329−105×) than pre-JWST consensus models. The high EWs of UV lines (≈15−35\AA) signal a rising star-formation history, with a ≈10× increase in the last 5 Myr (SFR5Myr/SFR50Myr=9.9+3.0−5.8). The source is extremely compact (circularized re=74+15−12 pc), and yet elongated (b/a=0.25+0.11−0.06), suggesting an AGN is not the dominant source of UV light. The steep UV slope (β=−2.5+0.2−0.2) implies negligible dust attenuation and a young stellar population. The absence of a strong damping wing provides tentative evidence that the immediate surroundings of MoM-z14 may be partially ionized at a redshift where virtually every reionization model predicts a ≈100% neutral fraction. The nitrogen emission and highly super-solar [N/C]>1 hint at an abundance pattern similar to local globular clusters that may have once hosted luminous supermassive stars. Since this abundance pattern is also common among the most ancient stars born in the Milky Way, we may be directly witnessing the formation of such stars in dense clusters, connecting galaxy evolution across the entire sweep of cosmic time.