A close look at the black hole masses and hot dusty toruses of the first quasars with MIRI-MRS
Sarah E. I. Bosman, Javier ‘Alvarez-M’arquez, Frederick B. Davies, Klaudia Protuv{s}ov’a, Joseph F. Hennawi, Jinyi Yang, Benedetta Spina, Luis Colina, Xiaohui Fan, G"oran "Ostlin, Fabian Walter, Feige Wang, Martin Ward, Almudena Alonso Herrero, Aaron J. Barth, Silvia Belladitta, Leindert Boogaard, Karina I. Caputi, Thomas Connor, Dominika v{D}urovv{c}’ikov’a, Anna-Christina Eilers, Alejandro Crespo G’omez, Jens Hjorth, Hyunsung D. Jun, Danial Langeroodi, Weizhe Liu, Alessandro Lupi, Chiara Mazzucchelli, John P. Pye, Pierluigi Rinaldi, Paul van der Werf, Marta Volonteri
arXiv:2511.02902v1 Announce Type: new
Abstract: 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 $7.08leq z7$ 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 $zarXiv:2511.02902v1 Announce Type: new
Abstract: 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 $7.08leq z7$ 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