Remarkably high mass and high velocity dispersion of molecular gas associated with a regular, absorption-selected type-I quasar

Abstract

We present 3-mm observations of the quasar J0015+1842 at z=2.63 with the NOrthern Extended Millimeter Array (NOEMA). Our data reveals molecular gas, traced via a Gaussian CO(3-2) line, with a remarkably large velocity dispersion (FWHM=1010+/-120 km/s) and corresponding to a total molecular mass MH2~(3.4-17)x10^10 Msun, depending on the adopted CO-to-H2 conversion factor alphaCO=(0.8-4.0) Msun (km/s pc^2)^-1. Assuming the 3-mm continuum emission is thermal, we derive a dust mass of the order of Mdust ~5x10^8 Msun. J0015+1842 is located in the molecular gas-rich region in the IR vs CO line luminosity diagram, in-between the main locus of main-sequence and sub-millimetre galaxies and that of most other AGNs targeted so far for CO measurements. While the large velocity dispersion of the CO line suggests a merging system, J0015+1842 is observed to be a regular, only very moderately dust-reddened (Av~0.3-0.4) type-I quasar from its UV-optical spectrum, from which we infer a mass of the super-massive black hole be around MBH~6x10^8 Msun. We suggest that J0015+1842 is observed at a galaxy evolutionary stage where a massive merger has brought significant amounts of gas towards an actively accreting super-massive black hole (quasar). While the host still contains a large amount of dust and molecular gas with high velocity dispersion, the quasar has already cleared the way towards the observer, likely through powerful outflows as recently revealed by optical observations of the same object. High angular resolution observations of this and similar systems} should help determining better the respective importance of evolution and orientation in the appearance of quasars and their host galaxies and have the potential to investigate early feedback and star-formation processes in galaxies in their quasar phases.

5 pages, 5 figures, accepted for publication in A\&A

References in corpus (23)

• A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity
• Highly-excited CO emission in APM08279+5255 at z=3.9
• The WISSH Quasars Project I. Powerful ionised outflows in hyper-luminous quasars
• 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
• How to quench a galaxy
• Quasar Feedback in the Ultraluminous Infrared Galaxy F11119+3257: Connecting the Accretion Disk Wind with the Large-Scale Molecular Outflow
• Molecular gas in three z~7 quasar host galaxies
• The Discovery of Gas-Rich, Dusty Starbursts in Luminous Reddened Quasars at $z\sim 2.5$ with ALMA
• ALMA observations of cold molecular gas in AGN hosts at z~1.5 - Evidence of AGN feedback?
• Evidence for feedback in action from the molecular gas content in the z~1.6 outflowing QSO XID2028
• NOEMA redshift measurements of bright Herschel galaxies
• BR1202-0725: An Extreme Multiple Merger at z = 4.7
• AGN feedback on molecular gas reservoirs in quasars at $z\sim$2.4
• SUPER IV. CO(J=3-2) properties of active galactic nucleus hosts at cosmic noon revealed by ALMA
• Gas, dust, and star formation in the positive AGN feedback candidate 4C 41.17 at z=3.8
• Proximate Molecular Quasar Absorbers: Excess of damped H2 systems at zabs~zQSO in SDSS DR14
• Molecular gas observations of the reddened quasar 3C 318
• Gas reservoir of a hyper-luminous QSO at z=2.6
• Resolving Disks & Mergers in $z\sim 2$ Heavily Reddened Quasars and their Companion Galaxies with ALMA
• A titanic interstellar medium ejection from a massive starburst galaxy at redshift 1.4
• Down-the-barrel observations of a multiphase quasar outflow at high redshift: VLT/X-shooter spectroscopy of the proximate molecular absorber at z=2.631 towards SDSS J001514+184212
• Alma Reveals A Gas-rich, Maximum-starburst In The Hyperluminous, Dust-obscured Quasar W0533-3401 AT $z\sim 2.9$

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