We present IRAM Plateau de Bure Interferometer observations of the 12CO(3-2) emission from two far-infrared luminous QSOs at z ~ 2.5 selected from the Herschel-ATLAS survey. These far-infrared bright QSOs were selected to have supermassive black holes (SMBHs) with masses similar to those thought to reside in sub-millimetre galaxies (SMGs) at z ~ 2.5; making them ideal candidates as systems in transition from an ultraluminous infrared galaxy phase to a sub-mm faint, unobscured, QSO. We detect 12CO(3-2) emission from both QSOs and we compare their baryonic, dynamical and SMBH masses to those of SMGs at the same epoch. We find that these far-infrared bright QSOs have similar dynamical but lower gas masses than SMGs. In particular we find that far-infrared bright QSOs have ~50+-23% less warm/dense gas than SMGs, which combined with previous results showing the QSOs lack the extended, cool reservoir of gas seen in SMGs, suggests that they are at a different evolutionary stage. This is consistent with the hypothesis that far-infrared bright QSOs represent a short (~1Myr) but ubiquitous phase in the transformation of dust obscured, gas-rich, starburst-dominated SMGs into unobscured, gas-poor, QSOs.
|Titolo:||The evolutionary connection between QSOs and SMGs: molecular gas in far-infrared luminous QSOs at z ~ 2.5|
|Autori:||Simpson J M; Smail I; Swinbank A M; Alexander D M; Auld R; Baes M; Bonfield D G; Clements D L; Cooray A; Coppin K E K; Danielson A L R; Dariush A; Dunne L; de Zotti G; Harrison C M; Hopwood R; Hoyos C; Ibar E; Ivison R J; Jarvis M J; Lapi A; Maddox S J; Page M J; Riechers D A; Valiante E; van der Werf P P|
|Rivista:||MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY|
|Data di pubblicazione:||2012|
|Digital Object Identifier (DOI):||10.1111/j.1365-2966.2012.21941.x|
|Appare nelle tipologie:||1.1 Journal article|