MOLECULAR GAS IN INFRARED ULTRALUMINOUS QSO HOSTS

Journal Article · Thu May 10 04:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/750/2/92· OSTI ID:22034538

Xia, X Y; Hao, C -N ^[1]; Gao, Y; Tan, Q H ^[2]; Mao, S ^[3]; Omont, A ^[4]; Flaquer, B O; Leon, S ^[5]; Cox, P ^[6]

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1. Tianjin Astrophysics Center, Tianjin Normal University, Tianjin 300387 (China)
2. Purple Mountain Observatory, Chinese Academy of Sciences, 2 West Beijing Road, Nanjing 210008 (China)
3. National Astronomical Observatories of China, 20A Datun Road, Chaoyang District, Beijing 100012 (China)
4. Institut d'Astrophysique de Paris, UMR7095, UPMC and CNRS, 98bis boulevard Arago, F-75014 Paris (France)
5. Instituto de Radioastronomia Milimetrica (IRAM), Avenida Divina Pastora 7, Nucleo Central, 18012 Granada (Spain)
6. Institut de Radio Astronomie Millimetrique (IRAM), F-38406 St. Martin d'Heres (France)

We report CO detections in 17 out of 19 infrared ultraluminous QSO (IR QSO) hosts observed with the IRAM 30 m telescope. The cold molecular gas reservoir in these objects is in a range of (0.2-2.1) Multiplication-Sign 10{sup 10} M{sub Sun} (adopting a CO-to-H{sub 2} conversion factor {alpha}{sub CO} = 0.8 M{sub Sun} (K km s{sup -1} pc{sup 2}){sup -1}). We find that the molecular gas properties of IR QSOs, such as the molecular gas mass, star formation efficiency (L{sub FIR}/L'{sub CO}), and CO (1-0) line widths, are indistinguishable from those of local ultraluminous infrared galaxies (ULIRGs). A comparison of low- and high-redshift CO-detected QSOs reveals a tight correlation between L{sub FIR} and L'{sub CO(1-0)} for all QSOs. This suggests that, similar to ULIRGs, the far-infrared emissions of all QSOs are mainly from dust heated by star formation rather than by active galactic nuclei (AGNs), confirming similar findings from mid-infrared spectroscopic observations by Spitzer. A correlation between the AGN-associated bolometric luminosities and the CO line luminosities suggests that star formation and AGNs draw from the same reservoir of gas and there is a link between star formation on {approx}kpc scale and the central black hole accretion process on much smaller scales.

• OSTI ID: 22034538
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 750; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASTRONOMY
ASTROPHYSICS
BLACK HOLES
BOLOMETERS
CARBON MONOXIDE
COMPARATIVE EVALUATIONS
CORRELATIONS
COSMIC DUST
DETECTION
GALACTIC EVOLUTION
GALAXIES
GALAXY NUCLEI
HYDROGEN
INFRARED RADIATION
LINE WIDTHS
LUMINOSITY
PHOTON EMISSION
RED SHIFT
STARS