Uncovering a Massive z ～ 7.7 Galaxy Hosting a Heavily Obscured Radio-loud Active Galactic Nucleus Candidate in COSMOS-Web

作者：Lambrides, Erini; Chiaberge, Marco; Long, Arianna S.; Liu, Daizhong; Akins, Hollis B.; Ptak, Andrew F.; Andika, Irham Taufik; Capetti, Alessandro; Casey, Caitlin M.; Champagne, Jaclyn B.; Chworowsky, Katherine; Clarke, Tracy E.; Cooper, Olivia R.; Ding, Xuheng; Dong, Dillon Z.; Faisst, Andreas L.; Forman, Jordan Y.; Franco, Maximilien; Gillman, Steven; Gozaliasl, Ghassem; Hall, Kirsten R.; Harish, Santosh; Hayward, Christopher C.; Hirschmann, Michaela; Hutchison, Taylor A.; Jahnke, Knud

来源：Astrophysical Journal Letters, 2024, 961(1): L25.

DOI：10.3847/2041-8213/ad11ee

• LUMINOUS QUASAR
• LEGACY SURVEY
• BLACK-HOLES
• REDSHIFT
• FIELD
• DISCOVERY
• UNIVERSE
• SKY
• AGN
• CONFIRMATION

In this Letter, we report the discovery of the highest redshift, heavily obscured, radio-loud (RL) active galactic nucleus (AGN) candidate selected using JWST NIRCam/MIRI, mid-IR, submillimeter, and radio imaging in the COSMOS-Web field. Using multifrequency radio observations and mid-IR photometry, we identify a powerful, RL, growing supermassive black hole with significant spectral steepening of the radio spectral energy distribution (f (1.28 GHz) similar to 2 mJy, q (24 mu m) = -1.1, alpha (1.28-3) (GHz) = - 1.2, Delta alpha = - 0.4). In conjunction with ALMA, deep ground-based observations, ancillary space-based data, and the unprecedented resolution and sensitivity of JWST, we find no evidence of AGN contribution to the UV/optical/near-infrared (NIR) data and thus infer heavy amounts of obscuration (N- H > 10(23) cm(-2)). Using the wealth of deep UV to submillimeter photometric data, we report a singular solution photo-z of z (phot) = 7.7(-0.3)(+0.4) and estimate an extremely massive host galaxy (log M-star=11.92 +/- 0.5M(circle dot)) hosting a powerful, growing supermassive black hole (L (Bol) = 4-12x x 10(46) erg s(-1)). This source represents the farthest known obscured RL AGN candidate, and its level of obscuration aligns with the most representative but observationally scarce population of AGN at these epochs.

• 单位
  东南大学; 北京大学; 中国科学院国家天文台