GN-z11 was photometrically selected as a luminous star-forming galaxy candidate at redshift z > 10 based on Hubble Space Telescope (HST) imaging data. Follow-up HST near-infrared grism observations detected a continuum break that was explained as the Ly-alpha break corresponding to z = 11.09 (+0.08-0.12). However, its accurate redshift remained unclear. Here we report a probable detection of three ultraviolet (UV) emission lines from GN-z11, which can be interpreted as the [C III] 1907, C III] 1909 doublet and O III] 1666 at z = 10.957+/-0.001 (when the Universe was only ~420 Myr old, or ~3% of its current age). This is consistent with the redshift of the previous grism observations, supporting GN-z11 as the most distant galaxy known to date. Its UV lines likely originate from dense ionized gas that is rarely seen at low redshifts, and its strong [C III] and C III] emission is partly due to an active galactic nucleus (AGN) or enhanced carbon abundance. GN-z11 is luminous and young, yet moderately massive, implying a rapid build-up of stellar mass in the past. Future facilities will be able to find the progenitors of such galaxies at higher redshift and probe the cosmic epoch in the beginning of re-ionization.
@article{arxiv.2012.06936,
title = {Evidence for GN-z11 as a luminous galaxy at redshift 10.957},
author = {Linhua Jiang and Nobunari Kashikawa and Shu Wang and Gregory Walth and Luis C. Ho and Zheng Cai and Eiichi Egami and Xiaohui Fan and Kei Ito and Yongming Liang and Daniel Schaerer and Daniel P. Stark},
journal= {arXiv preprint arXiv:2012.06936},
year = {2020}
}
Comments
Published in Nature Astronomy on Dec 14, 2020; 21 pages; authors' version