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

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

Bhatt, Maulik
;
Gallerani, Simona;Ferrara, Andrea;D'Odorico, Valentina;Valentini, Milena;Zana, Tommaso;Chakraborty, Srija
2024

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
2024
Settore FIS/05 - Astronomia e Astrofisica
Galaxies: high-redshift; Quasars: general; Quasars: supermassive black holes;
   BIGz: Building the Giants: accretion, feedback and assembly in z > 6 quasars
   MUR
   PRIN2022

   Italian Research Center on High-Performance Computing, Big Data and Quantum Computing
   MUR
   PNRR
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11384/143123
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