A direct black-hole mass measurement in a little red dot at high redshift

• 成果类型: Article
• 署名作者: Juodzbalis, Ignas; Marconcini, Cosimo; D'Eugenio, Francesco; Maiolino, Roberto; Marconi, Alessandro; Ubler, Hannah; Scholtz, Jan; Ji, Xihan; Jones, Gareth C.; Perna, Michele; Arribas, Santiago; Bennett, Jake S.; Bromm, Volker; Bunker, Andrew J.; Carniani, Stefano; Charlot, Stephane; Cresci, Giovanni; Dayal, Pratika; Egami, Eiichi; Fabian, Andrew; Inayoshi, Kohei; Isobe, Yuki; Ivey, Lucy R.; Koudmani, Sophie; Laporte, Nicolas; Liu, Boyuan; Lyu, Jianwei; Mazzolari, Giovanni; Monty, Stephanie; Parlanti, Eleonora; Perez-Gonzalez, Pablo G.; Robertson, Brant; Schneider, Raffaella; Sijacki, Debora; Tacchella, Sandro; Trinca, Alessandro; Valiante, Rosa; Volonteri, Marta; Witstok, Joris; Zhang, Saiyang
• 署名单位: University of Cambridge; University of Cambridge; University of Florence; Istituto Nazionale Astrofisica (INAF); University of London; University College London; Max Planck Society; Consejo Superior de Investigaciones Cientificas (CSIC); CSIC - Centro de Astrobiologia (INTA); Smithsonian Institution; University of Texas System; University of Texas Austin; University of Oxford; Scuola Normale Superiore di Pisa; Centre National de la Recherche Scientifique (CNRS); Sorbonne Universite; University of Groningen; Kapteyn Astronomical Institute; University of Toronto; University of Arizona; University of Cambridge; Peking University; Waseda University; University of Hertfordshire; University of Cambridge; Centre National de la Recherche Scientifique (CNRS); Aix-Marseille Universite; Centre National d'Etudes Spatiales (CNES); Ruprecht Karls University Heidelberg; University of California System; University of California Santa Cruz; Sapienza University Rome; University of Insubria; Istituto Nazionale Astrofisica (INAF); University of Copenhagen; Niels Bohr Institute; University of Texas System; University of Texas Austin; University of Texas System; University of Texas Austin
• 刊物名称: NATURE
• ISSN/ISSBN: 0028-0836; 1476-4687
• DOI: 10.1038/s41586-026-10579-4
• 发表日期: 2026-05-28
• 关键词: RADIO; dark; agn

摘要

Recent discoveries of faint active galactic nuclei (AGN) at the redshift frontier have revealed a plethora of broad H alpha emitters with optically red continua, named little red dots (LRDs)(1), which comprise 15-30% of the high-redshift broad-line AGN population(2). Owing to their peculiar properties(3, 4, 5-6), modelling LRDs with standard AGN scenarios has proven challenging. In particular, the validity of single-epoch virial mass estimates in determining the black-hole masses of LRDs has been called into question, with some models claiming that masses might be overestimated by up to two orders of magnitude(7, 8, 9-10). Here we report a direct, dynamical black-hole mass measurement in a strongly lensed LRD at a redshift of 7.04. The combination of lensing with deep spectroscopic data reveals a rotation curve that is inconsistent with a nuclear star cluster, yet can be well explained by Keplerian rotation around a point mass of 50 million solar masses, consistent with virial black-hole mass estimates. The Keplerian rotation leaves little room for any stellar component in a host galaxy, as we conservatively infer M-BH/M-* > 2 (where M-BH is the black-hole mass and M-* is the stellar mass). Such a 'naked' black hole, together with its near-pristine environment(11), indicates that this LRD is a massive black-hole seed caught in its earliest accretion phase.