The search for Population III: Confirmation of a HeII emitter with no metal lines at z=10.6

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Authors: Roberto Maiolino, Hannah Übler, Michele Perna, J. Witstok, Gareth C. Jones, Pablo G. Perez-Gonzalez, Kimihiko Nakajima, Elka Rusta, Stefania Salvadori, Sandro Tacchella, Piero Madau, J. Trussler
+40 more Francesco D'Eugenio, Xihan Ji, Jan Scholtz, Stefano Carniani, Y. Isobe, Harley Katz, Santiago Arribas, William M. Baker, Torsten Böker, Volker Bromm, Andrew J. Bunker, Stephane Charlot, Jacopo Chevallard, M. Curti, Emma Curtis-Lake, Daniel Eisenstein, Eiichi Egami, Andrea Ferrara, Luca Graziani, K. Hainline, Jakob M. Helton, Lucy R. Ivey, Benjamin Jonson, M. Koller, Nimisha Kumari, ALESSANDRO MARCONI, Giovanni Mazzolari, Nicolas Laporte, Eleonora Parlanti, Robert G. Pascalau, Laura Pentericci, Pierluigi Rinaldi, Brant Robertson, Bruno Rodríguez Del Pino, Raffaella Schneider, Alessandra Venditti, Giacomo Venturi, Christopher N. A. Willmer, Callum Witten, Sandra Zamora
Cited by: 2

Abstract

We report the confirmation of a HeII$λ$1640 emitter located at 3 pkpc from the galaxy GN-z11, at z=10.6. The detection, based on JWST NIRSpec-IFU high-resolution spectroscopy, confirms a previous claim based on medium-resolution spectroscopy. The HeII$λ$1640 identification is further supported by the independent detection of H$γ$ obtained by Übler et al. (2026) at the same location. The HeII emission is spectrally resolved in two components separated by 120 km/s. The Equivalent Width of the HeII emission is extremely high ($>$20 A). No metal lines are detected. We argue that Population III stars are the most plausible explanation for the observed He II emission, with no satisfactory alternative from other classes of sources or mechanisms.

Fields of Study & Subjects

Galaxies: Formation Evolution Phenomena Astrophysical Phenomena and Observations Astronomy and Astrophysical Research

Publication details

Journal / source
HAL AMU
Publication date
20 March 2026
Language
EN
Document type
Preprint