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arXiv · 2503.07964

Warm Gas in the Vicinity of a Supermassive Black hole 13 Billion Years Ago

Ken-ichi Tadaki·Federico Esposito·Livia Vallini·Takafumi Tsukui·Toshiki Saito·Daisuke Iono·Tomonari Michiyama
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Abstract

Quasars, powered by supermassive black holes (SMBH), are among the brightest objects in the universe. In the vicinity of an SMBH, X-ray photons from an active galactic nucleus (AGN) can heat the surrounding gas to several hundred kelvin. Here we report observations of dust continuum and CO J=13-12 and J=14-13 line emissions at a resolution of 130 parsecs in a luminous quasar at z=6. We successfully detected these high-J CO line emissions from warm gas in a compact disk component. The CO luminosity ratio in the central region of the compact disk is consistent with theoretical models in which X-ray heating dominates the CO excitation and the gas column density is as high as 10$^{25}$ cm$^{-2}$. This demonstrates that high-resolution observations of high-J CO lines are promising ways to identify extremely dust-obscured quasars in the early universe.

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Ken-ichi Tadaki, Federico Esposito, Livia Vallini, Takafumi Tsukui, Toshiki Saito, Daisuke Iono, Tomonari Michiyama. 2025-03-11. Warm Gas in the Vicinity of a Supermassive Black hole 13 Billion Years Ago. https://doi.org/10.1038/s41550-025-02505-x

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