Spatially Resolved Molecular Interstellar Medium in a z = 6.6 Quasar Host Galaxy
Abstract
We present high spatial resolution (~0.″4, 2.2 kpc) observations of the CO(6-5), CO(7-6), and [C I]369 μm lines and dust continuum emission from the interstellar medium (ISM) in the host galaxy of the quasar J0305-3150 at z = 6.6. These, together with archival [C II]158 μm data at a comparable spatial resolution, enable studies of the spatial distribution and kinematics between the ISM in different phases. When comparing the radial profiles of CO, [C II]158 μm, and the dust continuum, we find that the CO and dust continuum exhibit similar spatial distributions, both of which are less extended than the [C II]158 μm, indicating that the CO and dust continuum are tracing the same gas component, while the [C II]158 μm is tracing a more extended one. In addition, we derive the radial profiles of the [C II]158 μm/CO, [C II]158 μm/far-infrared (FIR), CO/FIR, and dust continuum S 98.7 GHz/S 258.1 GHz ratios. We find a decreasing S 98.7 GHz/S 258.1 GHz ratio with radius, possibly indicating a decrease of dust optical depth with increasing radius. We also detect some of the ISM lines and continuum emission in the companion galaxies previously discovered in the field around J0305-3150. Through comparing the line-to-line and line-to-FIR ratios, we find no significant differences between the quasar and its companion galaxies.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2022
- DOI:
- 10.3847/1538-4357/ac61d7
- arXiv:
- arXiv:2204.00793
- Bibcode:
- 2022ApJ...930...27L
- Keywords:
-
- Interstellar medium;
- Quasars;
- Submillimeter astronomy;
- AGN host galaxies;
- Interstellar dust;
- High-redshift galaxies;
- Early universe;
- Molecular gas;
- Interstellar atomic gas;
- 847;
- 1319;
- 1647;
- 2017;
- 836;
- 734;
- 435;
- 1073;
- 833;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- 12 pages, 6 figures, accepted for publication in ApJ