2008/09/04 by Dominik A. Riechers, Fabian Walter, Christopher L. Carilli +1 · 3 citations
Physics and Astronomy · #Active galactic nucleus #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Luminosity #Physics #Quasar #RADIUS #Redshift #astro-ph
paper · pdf · doi:10.1088/0004-637x/690/1/463
published as Astrophys.J.690:463-485,2009 · 25 pages, 12 figures, 6 tables, to appear in ApJ (accepted September 03, 2008)
arxiv created 2008/09/04 · openalex publication_date 2008/12/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We have mapped the molecular gas content in the host galaxy of the strongly lensed high-redshift quasar APM 08279+5255 (z = 3.911) with the Very Large Array at 0 farcs3 resolution. The CO(J = 1➝0) emission is clearly resolved in our maps. The CO(J = 1➝0) line luminosity derived from these maps is in good agreement with a previous single-dish measurement. In contrast to previous interferometer-based studies, we find that the full molecular gas reservoir is situated in two compact peaks separated by ≲0 farcs4. Our observations reveal, for the first time, that the emission from cold molecular gas is virtually co-spatial with the optical/near-infrared continuum emission of the central active galactic nucleus (AGN) in this source. This striking similarity in morphology indicates that the molecular gas is situated in a compact region close to the AGN. Based on the high-resolution CO maps, we present a revised model for the gravitational lensing in this system, which indicates that the molecular gas emission is magnified by only a factor of 4 (in contrast to previously suggested factors of 100). This model suggests that the CO is situated in a circumnuclear disk of ~550 pc radius that is possibly seen at an inclination of ≲25°, i.e., relatively close to face-on. From the CO luminosity, we derive a molecular gas mass of Mgas = 1.3x1011 M☉ for this galaxy. From the CO structure and linewidth, we derive a dynamical mass of M dyn sin2 i = 4.0x1010 M☉. Based on a revised mass estimate for the central black hole of Mbh = 2.3x1010 M☉ and the results of our molecular line study, we find that the mass of the stellar bulge of APM 08279+5255 falls short of the local M BH-σbulge relationship of nearby galaxies by more than an order of magnitude, lending support to recent suggestions that this relation may evolve with cosmic time and/or change toward the high-mass end.