Molecular Gas in Three z ∼ 7 Quasar Host Galaxies

Journal Article · Sun Aug 20 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA81CB· OSTI ID:22875893

Venemans, Bram P.; Walter, Fabian; Decarli, Roberto ^[1]; Ferkinhoff, Carl ^[2]; Weiß, Axel ^[3]; Findlay, Joseph R. ^[4]; McMahon, Richard G. ^[5]; Sutherland, Will J. ^[6]; Meijerink, Rowin ^[7]

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1. Max-Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)
2. Department of Physics, Winona State University, Winona, MN 55987 (United States)
3. Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany)
4. Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82070 (United States)
5. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)
6. Astronomy Unit, Queen Mary University of London, London, E1 4NS (United Kingdom)
7. Leiden Observatory, Leiden University, P.O. box 9513, NL-2300 RA Leiden (Netherlands)

We present ALMA band 3 observations of the CO(6–5), CO(7–6), and [C i] 369 μm emission lines in three of the highest-redshift quasar host galaxies at 6.62″, or ≳14 kpc) CO emission in all three quasar hosts. In two sources, we detect the continuum emission around 400 μm (rest-frame), and in one source we detect [C i] at low significance. We derive molecular gas reservoirs of (1–3) × 10{sup 10} M{sub ⊙} in the quasar hosts, i.e., approximately only 10 times the mass of their central supermassive black holes. The extrapolated [C ii]-to-CO(1–0) luminosity ratio is 2500–4200, consistent with measurements in galaxies at lower redshift. The detection of the [C i] line in one quasar host galaxy and the limit on the [C i] emission in the other two hosts enables a first characterization of the physical properties of the interstellar medium in z ∼ 7 quasar hosts. In the sources, the derived global CO/[C ii]/[C i] line ratios are consistent with expectations from photodissociation regions, but not X-ray-dominated regions. This suggest that quantities derived from the molecular gas and dust emission are related to ongoing star-formation activity in the quasar hosts, providing further evidence that the quasar hosts studied here harbor intense starbursts in addition to their active nucleus.

• OSTI ID: 22875893
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 845; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
BLACK HOLES
CARBON MONOXIDE
COSMIC DUST
COSMIC X-RAY SOURCES
COSMOLOGY
DETECTION
DISSOCIATION
EMISSION
GALAXIES
GALAXY NUCLEI
LUMINOSITY
MASS
PHOTOLYSIS
QUASARS
RED SHIFT
RESOLUTION
STARS