JADES NIRSpec Spectroscopy of GN-z11: Lyman-$α$ emission and possible enhanced nitrogen abundance in a $z=10.60$ luminous galaxy
Creators: name: Bunker, Andrew J.
name: Saxena, Aayush
name: Cameron, Alex J.
name: Willott, Chris J.
name: Curtis-Lake, Emma
name: Jakobsen, Peter
name: Carniani, Stefano
name: Smit, Renske
name: Maiolino, Roberto
name: Witstok, Joris
name: Curti, Mirko
name: D'Eugenio, Francesco
name: Jones, Gareth C.
name: Ferruit, Pierre
name: Arribas, Santiago
name: Charlot, Stephane
name: Chevallard, Jacopo
name: Giardino, Giovanna
name: de Graaff, Anna
name: Looser, Tobias J.
name: Luetzgendorf, Nora
name: Maseda, Michael V.
name: Rawle, Tim
name: Rix, Hans-Walter
name: Del Pino, Bruno Rodriguez
name: Alberts, Stacey
name: Egami, Eiichi
name: Eisenstein, Daniel J.
name: Endsley, Ryan
name: Hainline, Kevin
name: Hausen, Ryan
name: Johnson, Benjamin D.
name: Rieke, George
name: Rieke, Marcia
name: Robertson, Brant E.
name: Shivaei, Irene
name: Stark, Daniel P.
name: Sun, Fengwu
name: Tacchella, Sandro
name: Tang, Mengtao
name: Williams, Christina C.
name: Willmer, Christopher N. A.
name: Baker, William M.
name: Baum, Stefi
name: Bhatawdekar, Rachana
name: Bowler, Rebecca
name: Boyett, Kristan
name: Chen, Zuyi
name: Circosta, Chiara
name: Helton, Jakob M.
name: Ji, Zhiyuan
name: Lyu, Jianwei
name: Nelson, Erica
name: Parlanti, Eleonora
name: Perna, Michele
name: Sandles, Lester
name: Scholtz, Jan
name: Suess, Katherine A.
name: Topping, Michael W.
name: Uebler, Hannah
name: Wallace, Imaan E. B.
name: Whitler, Lily
Publisher: name: arXiv
Year: 2023
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present JADES JWST/NIRSpec spectroscopy of GN-z11, the most luminous candidate $z&gt;10$ Lyman break galaxy in the GOODS-North field with $M_{UV}=-21.5$. We derive a redshift of $z=10.603$ (lower than previous determinations) based on multiple emission lines in our low and medium resolution spectra over $0.8-5.3 μ$m. We significantly detect the continuum and measure a blue rest-UV spectral slope of $β=-2.4$. Remarkably, we see spatially-extended Lyman-$α$ in emission (despite the highly-neutral IGM expected at this early epoch), offset 555 km s$^{-1}$ redward of the systemic redshift. From our measurements of collisionally-excited lines of both low- and high-ionization (including [O II]$\lambda3727$, [Ne III]$λ3869$ and C III]$\lambda1909$) we infer a high ionization parameter ($\log U\sim -2$). We detect the rarely-seen N IV]$\lambda1486$ and N III]$\lambda1748$ lines in both our low and medium resolution spectra, with other high ionization lines seen in the low resolution spectrum such as He II (blended with O III]) and C IV (with a possible P-Cygni profile). Based on the observed rest-UV line ratios, we cannot conclusively rule out photoionization from AGN, although the high C III]/He II and N III]/He II ratios are compatible with a star-formation explanation. If the observed emission lines are powered by star formation, then the strong N III]$\lambda1748$ observed may imply an unusually high $N/O$ abundance. Balmer emission lines (H$γ$, H$δ$) are also detected, and if powered by star formation rather than an AGN we infer a star formation rate of $\sim 20-30 M_{\odot} yr^{-1}$ (depending on the IMF) and low dust attenuation. Our NIRSpec spectroscopy confirms that GN-z11 is a remarkable galaxy with extreme properties seen 430 Myr after the Big Bang.
description: Accepted for publication in Astronomy &amp; Astrophysics, 17 pages, 12 figures. Line fluxes updated