_version_ 1866912688203890688
author Bosman, Sarah E. I.
Álvarez-Márquez, Javier
Davies, Frederick B.
Protušová, Klaudia
Hennawi, Joseph F.
Yang, Jinyi
Spina, Benedetta
Colina, Luis
Fan, Xiaohui
Östlin, Göran
Walter, Fabian
Wang, Feige
Ward, Martin
Herrero, Almudena Alonso
Barth, Aaron J.
Belladitta, Silvia
Boogaard, Leindert
Caputi, Karina I.
Connor, Thomas
Ďurovčíková, Dominika
Eilers, Anna-Christina
Gómez, Alejandro Crespo
Hjorth, Jens
Jun, Hyunsung D.
Langeroodi, Danial
Liu, Weizhe
Lupi, Alessandro
Mazzucchelli, Chiara
Pye, John P.
Rinaldi, Pierluigi
van der Werf, Paul
Volonteri, Marta
author_facet Bosman, Sarah E. I.
Álvarez-Márquez, Javier
Davies, Frederick B.
Protušová, Klaudia
Hennawi, Joseph F.
Yang, Jinyi
Spina, Benedetta
Colina, Luis
Fan, Xiaohui
Östlin, Göran
Walter, Fabian
Wang, Feige
Ward, Martin
Herrero, Almudena Alonso
Barth, Aaron J.
Belladitta, Silvia
Boogaard, Leindert
Caputi, Karina I.
Connor, Thomas
Ďurovčíková, Dominika
Eilers, Anna-Christina
Gómez, Alejandro Crespo
Hjorth, Jens
Jun, Hyunsung D.
Langeroodi, Danial
Liu, Weizhe
Lupi, Alessandro
Mazzucchelli, Chiara
Pye, John P.
Rinaldi, Pierluigi
van der Werf, Paul
Volonteri, Marta
contents The presence of supermassive black holes (SMBHs, $M_\text{BH}\sim10^9 M_\odot$) at $z>7$ remains a puzzle. While their existence appears to require exotic formation or growth processes, it is possible that BH mass estimates are incorrect due to differences from the low-$z$ quasars where BH mass scaling relations are calibrated. In this work, we employ JWST MIRI-MRS spectroscopy to measure the rest-frame optical/IR properties of the four highest-redshift known luminous type-1 quasars at $7.08\leq z<7.64$. We use three new broad lines to measure updated BH masses, H$α$, Pa$α$ and Pa$β$, finding them to be in the range $(4-15)\cdot10^8 M_\odot$. Our black hole mass estimates from all tracers agree with each other and with previous, less accurate, ground-based measurements based on MgII. The flux ratios of the H lines deviate from expectations for case A and B recombination in the same way as in $z<3$ quasars, indicating similar physical conditions in the Broad Line Region. Rest-frame near-IR continuum emission from a hot dusty torus surrounding the accretion disc is unambiguously detected in all four objects. We model the emission with SKIRTOR and constrain the inclination (face-on) and the opening angle ($θ=40-60^\circ$) of the tori. These constraints are consistent for the four objects and with expectations from luminous quasars. We estimate a total dust mass $(1-4)\cdot10^6 M_\odot$ in the tori, corresponding to $(0.2-7)\%$ of the total dust in the quasar host galaxies. Given observed accretion rates, these SMBHs will deplete their tori in only $\sim5$ Myr. Overall, we confirm that $z>7$ SMBHs in quasars could not have grown from stellar-remnant BHs if the radiative efficiency of accretion is $10\%$. We also find no evidence that inferred BH masses and accretion processes in $z>7$ quasars differ significantly from their near-identical counterparts at $z<3$.
format Preprint
id arxiv_https___arxiv_org_abs_2511_02902
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A close look at the black hole masses and hot dusty toruses of the first quasars with MIRI-MRS
Bosman, Sarah E. I.
Álvarez-Márquez, Javier
Davies, Frederick B.
Protušová, Klaudia
Hennawi, Joseph F.
Yang, Jinyi
Spina, Benedetta
Colina, Luis
Fan, Xiaohui
Östlin, Göran
Walter, Fabian
Wang, Feige
Ward, Martin
Herrero, Almudena Alonso
Barth, Aaron J.
Belladitta, Silvia
Boogaard, Leindert
Caputi, Karina I.
Connor, Thomas
Ďurovčíková, Dominika
Eilers, Anna-Christina
Gómez, Alejandro Crespo
Hjorth, Jens
Jun, Hyunsung D.
Langeroodi, Danial
Liu, Weizhe
Lupi, Alessandro
Mazzucchelli, Chiara
Pye, John P.
Rinaldi, Pierluigi
van der Werf, Paul
Volonteri, Marta
Astrophysics of Galaxies
The presence of supermassive black holes (SMBHs, $M_\text{BH}\sim10^9 M_\odot$) at $z>7$ remains a puzzle. While their existence appears to require exotic formation or growth processes, it is possible that BH mass estimates are incorrect due to differences from the low-$z$ quasars where BH mass scaling relations are calibrated. In this work, we employ JWST MIRI-MRS spectroscopy to measure the rest-frame optical/IR properties of the four highest-redshift known luminous type-1 quasars at $7.08\leq z<7.64$. We use three new broad lines to measure updated BH masses, H$α$, Pa$α$ and Pa$β$, finding them to be in the range $(4-15)\cdot10^8 M_\odot$. Our black hole mass estimates from all tracers agree with each other and with previous, less accurate, ground-based measurements based on MgII. The flux ratios of the H lines deviate from expectations for case A and B recombination in the same way as in $z<3$ quasars, indicating similar physical conditions in the Broad Line Region. Rest-frame near-IR continuum emission from a hot dusty torus surrounding the accretion disc is unambiguously detected in all four objects. We model the emission with SKIRTOR and constrain the inclination (face-on) and the opening angle ($θ=40-60^\circ$) of the tori. These constraints are consistent for the four objects and with expectations from luminous quasars. We estimate a total dust mass $(1-4)\cdot10^6 M_\odot$ in the tori, corresponding to $(0.2-7)\%$ of the total dust in the quasar host galaxies. Given observed accretion rates, these SMBHs will deplete their tori in only $\sim5$ Myr. Overall, we confirm that $z>7$ SMBHs in quasars could not have grown from stellar-remnant BHs if the radiative efficiency of accretion is $10\%$. We also find no evidence that inferred BH masses and accretion processes in $z>7$ quasars differ significantly from their near-identical counterparts at $z<3$.
title A close look at the black hole masses and hot dusty toruses of the first quasars with MIRI-MRS
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2511.02902