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 - AstrophysicsReport as inadecuate




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 - Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We have mapped the molecular gas content in the host galaxy of the stronglylensed high redshift quasar APM 08279+5255 z=3.911 with the Very Large Arrayat 0.3- resolution. The COJ=1-0 emission is clearly resolved in our maps. TheCOJ=1-0 line luminosity derived from these maps is in good agreement with aprevious single-dish measurement. In contrast to previous interferometer-basedstudies, we find that the full molecular gas reservoir is situated in twocompact peaks separated by <~0.4-. Our observations reveal, for the first time,that the emission from cold molecular gas is virtually cospatial with theoptical-near-infrared continuum emission of the central AGN in this source.This striking similarity in morphology indicates that the molecular gas issituated in a compact region close to the AGN. Based on the high resolution COmaps, we present a revised model for the gravitational lensing in this system,which indicates that the molecular gas emission is magnified by only a factorof 4 in contrast to previously suggested factors of 100. This model suggeststhat the CO is situated in a circumnuclear disk of ~550 pc radius that ispossibly seen at an inclination of <~25 deg, i.e., relatively close to face-on.From the CO luminosity, we derive a molecular gas mass of M gas=1.3x10^11M sun for this galaxy. From the CO structure and linewidth, we derive adynamical mass of M dynsin i^2=4.0x10^10 M sun. Based on a revised massestimate for the central black hole of M BH=2.3x10^10 M sun and the results ofour molecular line study, we find that the mass of the stellar bulge of APM08279+5255 falls short of the local M BH-sigma bulge relationship of nearbygalaxies by more than an order of magnitude, lending support to recentsuggestions that this relation may evolve with cosmic time and-or change towardthe high mass end.



Author: Dominik A. Riechers 1,2,5, Fabian Walter 1, Christopher L. Carilli 3, Geraint F. Lewis 4 1 MPIA, Germany; 2 Caltech, USA; 3 NRAO,

Source: https://arxiv.org/







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