HYPERION: The cold interstellar medium of rapidly growing z > 6 quasars
6 affiliations
- 1INAF – Osservatorio Astronomico di Roma
- 2INAF, Osservatorio Astronomico di Trieste
- 3INAF – Osservatorio di Astrofisica e Scienza dello Spazio di Bologna
- 4Scuola Normale Superiore
- 5Observatorio de Madrid, OAN-IGN
- 6INAF – Osservatorio Astrofisico di Arcetri
Abstract
Luminous quasi-stellar objects (QSOs) at z > 6 host some of the most rapidly assembled super-massive black holes (SMBHs) in the early Universe. Characterising their cold interstellar medium (ISM) is essential to determine whether extreme SMBH growth is accompanied by similarly rapid host-galaxy assembly. We investigated the molecular gas, cold dust, star formation, gas-to-dust ratio, and ionised ISM of ten HYPerluminous quasars at the Epoch of ReionizatION (HYPERION) QSOs using new ALMA Band 3 observations targeting CO(6–5) and the underlying ∼100 GHz continuum, complemented by archival and literature ALMA/NOEMA data. We detect ∼100 GHz continuum emission in eight targets and CO(6–5) emission in four QSO hosts – J025–33, J083+11, J231–20, and J0252–0503 – as well as in the companion of J231–20. The inferred molecular gas masses are of order 1010 M⊙, while the non-detections imply upper limits of a few 109 M⊙, indicating a broad range of molecular reservoirs within the HYPERION population. For J025–33 and J083+11, the far-infrared (FIR) spectral energy distributions (SEDs) are well sampled and yield low dust temperatures Tdust = 36−7+13 K and 32−3+4 K, respectively, well below the average value for z > 6 QSOs. Combining gas and dust masses, we find a gas-to-dust ratio (GDR) for J083+11, GDR = 16−4+5, among the lowest measured in a high-redshift QSO host. We also detect [NII]λ205 µm emission in J025–33 and tentatively in J083+11, suggesting dense or highly structured ionised gas. Finally, we identify a tentative connection among Tdust, the X-ray photon index Γ, and the C IV velocity shift. These trends may indicate that more powerful winds redistribute dust away from the central active galactic nuclei (AGNs) heating source, lowering its temperature and weakening the connection between the large-scale dust reservoir and the X-ray corona. Overall, HYPERION QSOs emerge as a heterogeneous population in which SMBH growth, star formation, gas consumption, enrichment, and feedback are not necessarily synchronised.
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BibTeX
@article{maria2026hyperion,
title = {{HYPERION: The cold interstellar medium of rapidly growing z > 6 quasars}},
author = {Pierro Claudia Maria and Tripodi Roberta and Pentericci Laura and Salvestrini Francesco and Zappacosta Luca and Tortosa Alessia and Musiimenta Blessing and Piconcelli Enrico and Vallini Livia and Di Mascia Fabio and Esposito Federico and Feruglio Chiara and Vito Fabio and Zanchettin Maria Vittoria},
journal = {Astronomy \& Astrophysics},
year = {2026},
month = oct,
doi = {10.1051/0004-6361/202661464},
url = {https://doi.org/10.1051/0004-6361/202661464},
note = {CC BY},
}
RIS
TY - JOUR
TI - HYPERION: The cold interstellar medium of rapidly growing z > 6 quasars
AU - Pierro Claudia Maria
AU - Tripodi Roberta
AU - Pentericci Laura
AU - Salvestrini Francesco
AU - Zappacosta Luca
AU - Tortosa Alessia
AU - Musiimenta Blessing
AU - Piconcelli Enrico
AU - Vallini Livia
AU - Di Mascia Fabio
AU - Esposito Federico
AU - Feruglio Chiara
AU - Vito Fabio
AU - Zanchettin Maria Vittoria
PY - 2026
DA - 2026/10/24
JO - Astronomy & Astrophysics
DO - 10.1051/0004-6361/202661464
UR - https://doi.org/10.1051/0004-6361/202661464
AB - Luminous quasi-stellar objects (QSOs) at z > 6 host some of the most rapidly assembled super-massive black holes (SMBHs) in the early Universe. Characterising their cold interstellar medium (ISM) is essential to determine whether extreme SMBH growth is accompanied by similarly rapid host-galaxy assembly. We investigated the molecular gas, cold dust, star formation, gas-to-dust ratio, and ionised ISM of ten HYPerluminous quasars at the Epoch of ReionizatION (HYPERION) QSOs using new ALMA Band 3 observations targeting CO(6–5) and the underlying ∼100 GHz continuum, complemented by archival and literature ALMA/NOEMA data. We detect ∼100 GHz continuum emission in eight targets and CO(6–5) emission in four QSO hosts – J025–33, J083+11, J231–20, and J0252–0503 – as well as in the companion of J231–20. The inferred molecular gas masses are of order 1010 M⊙, while the non-detections imply upper limits of a few 109 M⊙, indicating a broad range of molecular reservoirs within the HYPERION population. For J025–33 and J083+11, the far-infrared (FIR) spectral energy distributions (SEDs) are well sampled and yield low dust temperatures Tdust = 36−7+13 K and 32−3+4 K, respectively, well below the average value for z > 6 QSOs. Combining gas and dust masses, we find a gas-to-dust ratio (GDR) for J083+11, GDR = 16−4+5, among the lowest measured in a high-redshift QSO host. We also detect [NII]λ205 µm emission in J025–33 and tentatively in J083+11, suggesting dense or highly structured ionised gas. Finally, we identify a tentative connection among Tdust, the X-ray photon index Γ, and the C IV velocity shift. These trends may indicate that more powerful winds redistribute dust away from the central active galactic nuclei (AGNs) heating source, lowering its temperature and weakening the connection between the large-scale dust reservoir and the X-ray corona. Overall, HYPERION QSOs emerge as a heterogeneous population in which SMBH growth, star formation, gas consumption, enrichment, and feedback are not necessarily synchronised.
SN - 0004-6361
SN - 1432-0746
ER -