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Title: ALMA observations of a candidate molecular outflow in an obscured quasar

We present Atacama Large Millimeter/Submillimeter Array CO (1-0) and CO (3-2) observations of SDSS J135646.10+102609.0, an obscured quasar and ultra-luminous infrared galaxy with two merging nuclei and a known 20 kpc scale ionized outflow. The total molecular gas mass is M{sub mol}≈9{sub −6}{sup +19}×10{sup 8} M{sub ☉}, mostly distributed in a compact rotating disk at the primary nucleus (M{sub mol} ≈ 3 × 10{sup 8} M{sub ☉}) and an extended tidal arm (M{sub mol} ≈ 5 × 10{sup 8} M{sub ☉}). The tidal arm is one of the most massive molecular tidal features known; we suggest that it is due to the lower chance of shock dissociation in this elliptical/disk galaxy merger. In the spatially resolved CO (3-2) data, we find a compact (r ≈ 0.3 kpc) high-velocity (v ≈ 500 km s{sup –1}) redshifted feature in addition to the rotation at the N nucleus. We propose a molecular outflow as the most likely explanation for the high-velocity gas. The outflowing mass of M{sub mol} ≈ 7 × 10{sup 7} M{sub ☉} and the short dynamical time of t{sub dyn} ≈ 0.6 Myr yield a very high outflow rate of M-dot{sub mol}≈350 M{sub ☉} yr{sup –1} and can deplete themore » gas in a million years. We find a low star formation rate (<16 M{sub ☉} yr{sup –1} from the molecular content and <21 M{sub ☉} yr{sup –1} from the far-infrared spectral energy distribution decomposition) that is inadequate to supply the kinetic luminosity of the outflow ( E-dot ≈3×10{sup 43} erg s{sup –1}). Therefore, the active galactic nucleus (AGN), with a bolometric luminosity of 10{sup 46} erg s{sup –1}, likely powers the outflow. The momentum boost rate of the outflow ( p-dot /(L{sub bol}/c)≈3) is lower than typical molecular outflows associated with AGNs, which may be related to its compactness. The molecular and ionized outflows are likely two distinct bursts induced by episodic AGN activity which varies on a timescale of 10{sup 7} yr.« less
Authors:
;  [1] ;  [2] ;  [3]
  1. Department of Astrophysics, Princeton University, Princeton, NJ 08540 (United States)
  2. Department of Physics and Astronomy, Bloomberg Center, Johns Hopkins University, Baltimore, MD 21218 (United States)
  3. Institut d'Astrophysique Spatiale, CNRS, Université Paris-Sud, Bat. 120-121, F-91405 Orsay (France)
Publication Date:
OSTI Identifier:
22365450
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 790; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BOLOMETERS; CARBON MONOXIDE; DECOMPOSITION; DISSOCIATION; EMISSION; ENERGY SPECTRA; GALAXIES; GALAXY NUCLEI; INTERACTIONS; LUMINOSITY; MASS; QUASARS; RED SHIFT; ROTATION; STARS; VELOCITY