Detection of the [O i] 63 μm emission line from the z=6.04 quasar J2054-0005
Journal article, 2025
We report the highest-redshift detection of [O i] 63 mu m from a luminous quasar, J2054-0005, at z=6.04 based on the Atacama Large Millimeter/sub-millimeter Array (ALMA) Band 9 observations. The [O i] 63 mu m line luminosity is (4.5 +/- 1.5)x10(9)L(circle dot), corresponding to the [O i] 63 mu m-to-far-infrared luminosity ratio of approximate to 6.7 x10(-4), which is consistent with the value obtained in the local Universe. Remarkably, [O i] 63 mu m is as bright as [C ii] 158 mu m, resulting in the [O i]-to-[C ii] line luminosity ratio of 1.3 +/- 0.5. Based on a careful comparison of the luminosity ratios of [O i] 63 mu m, [C ii] 158 mu m, and dust continuum emission to models of photodissociation regions, we find that J2054-0005 has a gas density log(n(H)/cm(-3))=3.7 +/- 0.3 and an incident far-ultraviolet radiation field of log(G/G(0))=3.0 +/- 0.1, showing that [O i] 63 mu m serves as an important coolant of the dense and warm gas in J2054-0005. A close examination of the [O i] and [C ii] line profiles suggests that the [O i] line may be partially self-absorbed; however, deeper observations are needed to verify this conclusion. Regardless, the gas density and incident radiation field are in broad agreement with the values obtained in nearby star-forming galaxies and objects with [O i] 63 mu m observations at z=1-3 with the Herschel Space Observatory. These results demonstrate the power of ALMA high-frequency observations targeting [O i] 63 mu m to examine the properties of photodissociation regions in high-redshift galaxies.
galaxies: active
galaxies: high-redshift
galaxies: ISM
quasars: general
Author
Nozomi Ishii
Systems Engineering Consultants (SEC)
University of Tsukuba
Takuya Hashimoto
University of Tsukuba
Carl Ferkinhoff
Winona State University (WSU)
Matus Rybak
Netherlands Institute for Space Research (SRON)
Delft University of Technology
Leiden University
Akio K. Inoue
Waseda University
Tomonari Michiyama
Shunan University
Darko Donevski
National Centre for Nuclear Research
International School for Advanced Studies (SISSA
Seiji Fujimoto
University of Texas
Dragan Salak
Hokkaido University
Hiroshi Matsuo
The Graduate University for Advanced Studies (SOKENDAI)
National Astronomical Observatory of Japan
University of Tsukuba
Ken Mawatari
University of Tsukuba
Yoichi Tamura
Nagoya University
University of Tsukuba
Takuma Izumi
National Astronomical Observatory of Japan
The Graduate University for Advanced Studies (SOKENDAI)
Tohru Nagao
Ehime University
Yurina Nakazato
University of Tokyo
Wataru Osone
University of Tsukuba
Yuma Sugahara
Waseda University
Mitsutaka Usui
University of Tsukuba
Koki Wakasugi
University of Tsukuba
Hidenobu Yajima
University of Tsukuba
Tom Bakx
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Yoshinobu Fudamoto
Chiba University
Romain A. Meyer
University of Geneva
Fabian Walter
Max Planck Society
Naoki Yoshida
University of Tokyo
Publication of the Astronomical Society of Japan
0004-6264 (ISSN) 2053051x (eISSN)
Vol. 77 1 139-148Subject Categories (SSIF 2011)
Astronomy, Astrophysics and Cosmology
Atom and Molecular Physics and Optics
DOI
10.1093/pasj/psae105