The molecular gas content of ULIRG type 2 quasars at z < 1

Abstract

We present new results of CO(1-0) spectroscopic observations of 4 SDSS type 2 quasars (QSO2) at z$\sim$0.3, observed with the 30m IRAM telescope. The QSO2 have infrared luminosities in the ULIRG (UltraLuminous Infrared Galaxies) regime. We confirm the CO(1-0) detection in one of our 4 QSO2, SDSS J1543-00, with $L_{CO}^{\prime }$ and $M_{H_2}$ (1.2$\pm$0.2) $\times$10${}^{10}$ K km s${}^{-1}$ pc${}^2$ and (9.4$\pm$1.4)$\times$10${}^9$ M${}_{\odot }$, respectively. The CO(1-0) line has $FWHM=$575$\pm$102 km s${}^{-1}$. No CO(1-0) emission is detected in SDSS J0903+02, SDSS J1337-01, SDSS J1520-01 above 3 sigma, yielding upper limits on $M(H_2)\sim$ 9.6, 4.3 and 5.1 $\times$10${}^9$ M${}_{\odot }$ respectively. Together with CO measurements of 9 QSO2 at $z\sim$0.3-1.0 from the ULIRG sample by Combes et al. (2011, 2013), we expand previous studies of the molecular gas content of intermediate $z$ QSO2 into the ULIRG regime. We discuss the location of the 13 ULIRG QSO2 at $z<$1 with available $L_{CO}^{\prime }$ measurements in the $L_{CO}^{\prime }$ vs. $z$ and $L_{CO}^{\prime }$ vs. $L_{FIR}$ diagrams, in comparison with other QSO1 and ULIRG star forming samples.

4 pages, 2 figures, Accepted for publication in A&A

References in corpus (11)

• Evidence of enhanced star formation efficiency in luminous and ultraluminous infrared galaxies
• CO(1-0) in z >/~ 4 Quasar Host Galaxies: No Evidence for Extended Molecular Gas Reservoirs
• Testing the Evolutionary Link Between Submillimetre Galaxies and Quasars: CO Observations of QSOs at z~2
• HCN Observations of Dense Star-Forming Gas in High Redshift Galaxies
• Imaging the Molecular Gas in a z=3.9 Quasar Host Galaxy at 0.3" Resolution: A Central, Sub-Kiloparsec Scale Star Formation Reservoir in APM 08279+5255
• Dense Molecular Gas and the Role of Star Formation in the Host Galaxies of Quasi-Stellar Objects
• Molecular gas in nearby low-luminosity QSO host galaxies
• Large amounts of optically-obscured star formation in the host galaxies of some type-2 quasars
• Molecular gas in QSO host galaxies at z>5
• Properties of the molecular gas in a starbursting QSO at z=1.83 in the COSMOS field
• A population of high-redshift type-2 quasars-II. Radio Properties

Cited by in corpus (4)

• AGN Feedback and Star Formation of Quasar Host Galaxies: Insights from the Molecular Gas
• The triggering mechanism and properties of ionized outflows in the nearest obscured quasars
• Integral field spectroscopy of nearby QSOs II. The molecular gas content and condition for star formation
• A low-luminosity type-1 QSO sample: IV. Molecular gas contents and conditions of star formation in three nearby Seyfert galaxies