Is GN-z11 powered by a super-Eddington massive black hole?
Journal
Date Issued
2024
Author(s)
Bhatt, Maulik
•
Gallerani, Simona
•
Ferrara, Andrea
•
Mazzucchelli, Chiara
•
•
•
Zana, Tommaso
•
Farina, Emanuele Paolo
•
Chakraborty, Srija
Abstract
Context. Observations of z ∼ 6 quasars powered by supermassive black holes (SMBHs; MBH ∼ 108 − 10 M⊙) challenge our current understanding of early black hole (BH) formation and evolution. The advent of the James Webb Space Telescope (JWST) has enabled the study of massive BHs (MBHs; MBH ∼ 106 − 7 M⊙) up to z ∼ 11, thus bridging the properties of z ∼ 6 quasars to their ancestors.
Aims: The JWST spectroscopic observations of GN-z11, a well-known z = 10.6 star-forming galaxy, have been interpreted with the presence of a super-Eddington (Eddington ratio ≡ λEdd ∼ 5.5) accreting MBH. To test this hypothesis, we used a zoom-in cosmological simulation of galaxy formation and BH co-evolution.
Methods: We first tested the simulation results against the observed probability distribution function (PDF) of λEdd found in z ∼ 6 quasars. Then, in the simulation we selected the BHs that satisfy the following criteria: (a) 10 < z < 11, (b) MBH > 106 M⊙. Next, we applied the extreme value statistics to the PDF of λEdd resulting from the simulation.
Results: We find that the probability of observing a z ∼ 10 − 11 MBH accreting with λEdd ∼ 5.5 in the volume surveyed by JWST is very low (< 0.2%). We compared our predictions with those in the literature, and discussed the main limitations of our work.
Conclusions: Our simulation cannot explain the JWST observations of GN-z11. This might be due to: (i) poor resolution and statistics in simulations, (ii) simplistic sub-grid models (e.g. BH accretion and seeding), (iii) uncertainties in the data analysis and interpretation.
Aims: The JWST spectroscopic observations of GN-z11, a well-known z = 10.6 star-forming galaxy, have been interpreted with the presence of a super-Eddington (Eddington ratio ≡ λEdd ∼ 5.5) accreting MBH. To test this hypothesis, we used a zoom-in cosmological simulation of galaxy formation and BH co-evolution.
Methods: We first tested the simulation results against the observed probability distribution function (PDF) of λEdd found in z ∼ 6 quasars. Then, in the simulation we selected the BHs that satisfy the following criteria: (a) 10 < z < 11, (b) MBH > 106 M⊙. Next, we applied the extreme value statistics to the PDF of λEdd resulting from the simulation.
Results: We find that the probability of observing a z ∼ 10 − 11 MBH accreting with λEdd ∼ 5.5 in the volume surveyed by JWST is very low (< 0.2%). We compared our predictions with those in the literature, and discussed the main limitations of our work.
Conclusions: Our simulation cannot explain the JWST observations of GN-z11. This might be due to: (i) poor resolution and statistics in simulations, (ii) simplistic sub-grid models (e.g. BH accretion and seeding), (iii) uncertainties in the data analysis and interpretation.
Volume
686
Start page
A141
Issn Identifier
0004-6361
Ads BibCode
2024A&A...686A.141B
Rights
open.access
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