University of Leicester
Browse
aa47869-23.pdf (6.81 MB)

A benchmark for extreme conditions of the multiphase interstellar medium in the most luminous hot dust-obscured galaxy at z = 4.6

Download (6.81 MB)
journal contribution
posted on 2024-03-15, 10:38 authored by Román Fernández Aranda, Tanio Díaz Santos, Evanthia Hatziminaoglou, Roberto J Assef, Manuel Aravena, Peter RM Eisenhardt, Carl Ferkinhoff, Antonio Pensabene, Thomas Nikola, Paola Andreani, Amit Vishwas, Gordon J Stacey, Roberto Decarli, Andrew W Blain, Drew Brisbin, Vassilis Charmandaris, Hyunsung D Jun, Guodong Li, Mai Liao, Lee R Martin, Daniel Stern, Chao-Wei Tsai, Jingwen Wu, Dejene Zewdie
WISE J224607.6–052634.9 (W2246–0526) is a hot dust-obscured galaxy at z = 4.601, and the most luminous obscured quasar known to date. W2246–0526 harbors a heavily obscured supermassive black hole that is most likely accreting above the Eddington limit. We present observations with the Atacama Large Millimeter/submillimeter Array (ALMA) in seven bands, including band 10, of the brightest far-infrared (FIR) fine-structure emission lines of this galaxy: [OI]63 μm, [OIII]88 μm, [NII]122 μm, [OI]145 μm, [CII]158 μm, [NII]205 μm, [CI]370 μm, and [CI]609 μm. A comparison of the data to a large grid of CLOUDY radiative transfer models reveals that a high hydrogen density (nH ∼ 3 × 103 cm−3) and extinction (AV ∼ 300 mag), together with extreme ionization (log(U) = − 0.5) and a high X-ray to UV ratio (αox ≥ −0.8) are required to reproduce the observed nuclear line ratios. The values of αox and U are among the largest found in the literature and imply the existence of an X-ray-dominated region (XDR). In fact, this component explains the a priori very surprising non-detection of the [OIII]88 μm emission line, which is actually suppressed, instead of boosted, in XDR environments. Interestingly, the best-fitted model implies higher X-ray emission and lower CO content than what is detected observationally, suggesting the presence of a molecular gas component that should be further obscuring the X-ray emission over larger spatial scales than the central region that is being modeled. These results highlight the need for multiline infrared observations to characterize the multiphase gas in high redshift quasars and, in particular, W2246–0526 serves as an extreme benchmark for comparisons of interstellar medium conditions with other quasar populations at cosmic noon and beyond.

History

Author affiliation

College of Science & Engineering/Physics & Astronomy

Version

  • VoR (Version of Record)

Published in

Astronomy & Astrophysics

Volume

682

Pagination

A166 - A166

Publisher

EDP Sciences

issn

0004-6361

eissn

1432-0746

Copyright date

2024

Available date

2024-03-15

Language

en

Deposited by

Professor Andrew Blain

Deposit date

2024-03-14

Rights Retention Statement

  • No

Usage metrics

    University of Leicester Publications

    Categories

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC