Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published January 1, 2009 | Published
Journal Article Open

Imaging the Molecular Gas in A z=3.9 Quasar Host Galaxy at 0\farcs3 Resolution: A Central, Sub-Kilparsex Scale Star Formation Reservoir in APM 08279+5255

Abstract

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 = 1.3x10^11 M☉ for this galaxy. From the CO structure and linewidth, we derive a dynamical mass of M dyn sin^2 i = 4.0x10^10 M☉. Based on a revised mass estimate for the central black hole of Mbh = 2.3x10^10 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.

Additional Information

© 2009. The American Astronomical Society. Received 2007 October 10; accepted 2008 September 3; published 2008 December 1. Print publication: Issue 1 (2009 January 1). We thank Dennis Downes, Axel Weiß, Rob Ivison, Melanie Krips, and Vernesa Smolčić for helpful discussions, and the anonymous referee for a critical reading of this manuscript. We also thank Rob Ivison for making his archival VLA data available, and Eiichi Egami and George Chartas for providing NIR and X-ray images of APM 08279+5255. D.R. acknowledges support from NASA through Hubble Fellowship grant HST-HF-01212.01-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS 5-26555, and from the Deutsche Forschungsgemeinschaft (DFG) Priority Program 1177. C.C. acknowledges support from the Max-Planck-Gesellschaft and the Alexander von Humboldt-Stiftung through the Max-Planck-Forschungspreis 2005. The National Radio Astronomy Observatory (NRAO) is operated by Associated Universities Inc., under cooperative agreement with the National Science Foundation. This research has made use of the NRAO Data Archive System. Some of the data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NAG5-7584 and by other grants and contracts. This research has made use of NASA's Astrophysics Data System.

Attached Files

Published - RIEapj09.pdf

Files

RIEapj09.pdf
Files (1.2 MB)
Name Size Download all
md5:18b23ae0dd6c322350c38caafecdd1d1
1.2 MB Preview Download

Additional details

Created:
August 20, 2023
Modified:
October 17, 2023