A high black-hole-to-host mass ratio in a lensed AGN in the early Universe
Charlot, Stéphane; Glazebrook, Karl; Labbé, Ivo; van Dokkum, Pieter; Fujimoto, Seiji; Bezanson, Rachel; Price, Sedona H.; Nelson, Erica; Stark, Daniel P.; Endsley, Ryan; Juneau, Stéphanie; Greene, Jenny E.; Marchesini, Danilo; Curtis-Lake, Emma; de Graaff, Anna; Williams, Christina C.; Leja, Joel; Whitaker, Katherine E.; Brammer, Gabriel B.; Goulding, Andy D.; Zitrin, Adi; Oesch, Pascal A.; Atek, Hakim; Miller, Tim B.; Fudamoto, Yoshinobu; Wang, Bingjie; Weaver, John R.; Kokorev, Vasily; Chemerynska, Iryna; Dayal, Pratika; Furtak, Lukas J.; Setton, David J.; Cutler, Sam E.; Pan, Richard; Feldmann, Robert; Plat, Adèle; Bogdán, Ákos; Maseda, Micheal V.
Israel, Australia, United States, Netherlands, France, Germany, Denmark, United Kingdom, Switzerland, Japan
Abstract
Early JWST observations have uncovered a population of red sources that might represent a previously overlooked phase of supermassive black hole growth1-3. One of the most intriguing examples is an extremely red, point-like object that was found to be triply imaged by the strong lensing cluster Abell 2744 (ref. 4). Here we present deep JWST/NIRSpec observations of this object, Abell2744-QSO1. The spectroscopy confirms that the three images are of the same object, and that it is a highly reddened (AV ≃ 3) broad emission line active galactic nucleus at a redshift of zspec = 7.0451 ± 0.0005. From the width of Hβ (full width at half-maximum = 2,800 ± 250 km s−1), we derive a black hole mass of MBH=4−1+2×1 07M⊙ . We infer a very high ratio of black-hole-to-galaxy mass of at least 3%, an order of magnitude more than that seen in local galaxies5 and possibly as high as 100%. The lack of strong metal lines in the spectrum together with the high bolometric luminosity (Lbol = (1.1 ± 0.3) × 1045 erg s−1) indicate that we are seeing the black hole in a phase of rapid growth, accreting at 30% of the Eddington limit. The rapid growth and high black-hole-to-galaxy mass ratio of Abell2744-QSO1 suggest that it may represent the missing link between black hole seeds6 and one of the first luminous quasars7.