# Is GN-z11 powered by a super-Eddington massive black hole?

**Authors:** Maulik Bhatt, Simona Gallerani, Andrea Ferrara, Chiara Mazzucchelli, Valentina D'Odorico, Milena Valentini, Tommaso Zana, Emanuele Paolo Farina, Srija Chakraborty  
**arXiv:** [2401.13733](https://arxiv.org/abs/2401.13733)  
**Date:** 2024-01-24  
**Summary page:** https://www.summarizepaper.com/en/paper/2401.13733v1/

## Key points

- Observations of quasars at redshift $z \sim 6$ have challenged our understanding of early black hole formation and evolution.
- Quasars at $z \sim 6$ are powered by super-massive black holes (SMBHs) with masses of $M_{\rm BH} \sim 10^{8-10}\, M_\odot$.
- The James Webb Space Telescope (JWST) allows the study of massive black holes (MBHs) with masses of $M_{\rm BH}\sim 10^{6-7} \ \mathrm{M}_\odot$ up to redshift $z\sim 11".
- A zoom-in cosmological simulation is used to test the hypothesis that GN-z11, a star-forming galaxy at redshift $z=10.6$, is powered by a super-Eddington accreting MBH with an Eddington ratio ($\lambda_{\rm Edd}$) of approximately 5.5.
- The simulation results are compared against observations and the probability of observing such a massive black hole at redshifts around 10-11 is found to be very low (<0.5%).
- There may be additional factors or uncertainties involved in understanding early black hole formation and evolution.
- The limitations of the simulation are discussed and it is acknowledged that it cannot fully explain the JWST observations of GN-z11.
- This study challenges the interpretation of JWST observations and highlights the need for further research on early black hole formation and evolution.

## Summary

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Observations of quasars at redshift $z \sim 6$ have challenged our understanding of early black hole formation and evolution. These quasars are powered by super-massive black holes (SMBHs) with masses of $M_{\rm BH} \sim 10^{8-10}\, M_\odot$. However, the James Webb Space Telescope (JWST) has provided an opportunity to study massive black holes (MBHs) with masses of $M_{\rm BH}\sim 10^{6-7} \ \mathrm{M}_\odot$ up to redshift $z\sim 11$, bridging the properties of quasars at $z\sim 6$ to their ancestors. In this study, the authors use a zoom-in cosmological simulation to test the hypothesis that GN-z11, a well-known star-forming galaxy at redshift $z=10.6$, is powered by a super-Eddington accreting MBH with an Eddington ratio ($\lambda_{\rm Edd}$) of approximately 5.5. To validate their simulation results, they compare them against observations and find that the probability of observing such a massive black hole at redshifts around 10-11 is very low (<0.5%). This suggests that there may be additional factors or uncertainties involved in understanding early black hole formation and evolution. The authors discuss the limitations of their work and acknowledge that their simulation cannot fully explain the JWST observations of GN-z11. In conclusion, this study challenges the interpretation of JWST observations and highlights the need for further research on early black hole formation and evolution.