GN-z11: Witnessing the formation of second-generation stars and an accreting massive black hole in a massive star cluster
F. D’Antona, Enrico Vesperini, F. Calura, P. Ventura, A. D’Ercole, V. Caloi, A. F. Marino, A. P. Milone, F. Dell’Agli, M. Tailo
Abstract
We explore the possibility of the N -rich young proto-galaxy GN-z11, recently observed at z = 10.6 by JWST, being the result of the formation of second generation stars from pristine gas and asymptotic giant branch (AGB) ejecta in a massive globular cluster or nuclear star cluster. We show that a second generation forming out of gas polluted by the ejecta of massive AGB stars and mixed with gas of a standard composition accounts for the unusually large N/O in the GN-z11 spectrum. The timing of the evolution of massive (4–7.5 M ⊙ ) AGBs also provides a favorable environment for the growth of a central stellar mass black hole to the AGN stage observed in GN-z11. According to our model, the progenitor system was born when the age of the Universe was ≃260 − 380 Myr, well within the bounds of the pre-reionization epoch.