Extreme Enrichment at Cosmic Dawn: Three FeII-Strong Quasars at z > 6 from the JWST Aether survey

@misc{gloudemans2026extreme,
  title = {{Extreme Enrichment at Cosmic Dawn: Three FeII-Strong Quasars at z > 6 from the JWST Aether survey}},
  author = {Anniek J. Gloudemans and Emanuele Paolo Farina and Roberto Decarli and Klaudia Protušová and Fabrizio Arrigoni Battaia and Eduardo Bañados and Aaron J. Barth and Silvia Belladitta and Manuela Bischetti and Hyunseop Choi and Dominika Ďurovčíková and Anna-Christina Eilers and Simona Gallerani and Thales A. Gutcke and Luca Ighina and Brian C. Lemaux and Federica Loiacono and Yoshiki Matsuoka and Chiara Mazzucchelli and Silvia Onorato and Hyewon Suh and Fabian Walter and Feige Wang and Julien Wolf and Jinyi Yang},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.19459},
  eprint = {2609.19459},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.19459},
}

TY  - UNPB
TI  - Extreme Enrichment at Cosmic Dawn: Three FeII-Strong Quasars at z > 6 from the JWST Aether survey
AU  - Anniek J. Gloudemans
AU  - Emanuele Paolo Farina
AU  - Roberto Decarli
AU  - Klaudia Protušová
AU  - Fabrizio Arrigoni Battaia
AU  - Eduardo Bañados
AU  - Aaron J. Barth
AU  - Silvia Belladitta
AU  - Manuela Bischetti
AU  - Hyunseop Choi
AU  - Dominika Ďurovčíková
AU  - Anna-Christina Eilers
AU  - Simona Gallerani
AU  - Thales A. Gutcke
AU  - Luca Ighina
AU  - Brian C. Lemaux
AU  - Federica Loiacono
AU  - Yoshiki Matsuoka
AU  - Chiara Mazzucchelli
AU  - Silvia Onorato
AU  - Hyewon Suh
AU  - Fabian Walter
AU  - Feige Wang
AU  - Julien Wolf
AU  - Jinyi Yang
PY  - 2026
DA  - 2026/09/16
PB  - arXiv
DO  - 10.48550/arxiv.2609.19459
UR  - https://arxiv.org/abs/2609.19459
AB  - We present three outliers on the quasar main sequence at z>6, as revealed by JWST/NIRSpec IFU observations from the Aether survey, a program targeting ~200 quasars at cosmic dawn. The quasars, J0216-5226, J0320-3521, and J1429+5447, exhibit exceptionally strong FeII emission and weak Hβ and [OIII] lines, indicating rapid chemical enrichment within the first Gyr of cosmic history. Their FeII strengths (R_FeII,λ4570 ≡ EW_FeII/EW_Hβ) range between ~2.5-3.6, placing them among the top ~3% of SDSS quasars at (0≲ z≲ 1). The Hα emission lines of J0216-5226 and J1429+5447 imply black hole masses of ∼1−7×10^9 M_⊙ with λ_Edd∼0.1−0.6, comparable to typical high-z quasars, although virial black hole masses may be systematically overestimated in strong FeII emitters. In contrast, J0320-3521 hosts a lower mass black hole of ∼0.2−2×10^9 M_⊙, suggesting possible super-Eddington rate accretion with λ_Edd~0.5-6.0. The IFU data of J0320-3521 reveal a distinct emission-line region at a projected distance of ~1.5 kpc, consistent with either an interacting companion or ionized gas associated to the quasar. We further identify a complex environment around J1429+5447, including two candidate companion galaxies or extended ionized gas structures. These quasars with bright emission-line regions, J0320-3521 and J1429+5447, are radio-loud sources, while J0216-5226 remains undetected in radio (R_5GHz, 3σ≲4). Together, these results confirm previous findings that highly enriched, rapidly growing black holes were already in place at cosmic dawn. Despite the small sample size, our results further highlight the diversity in environment and radio-jet properties among quasars that otherwise share the same extreme region of the quasar fundamental plane.
ER  -