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Detecting Low-Order CO Emission from z ≳ 4 Quasar Host Galaxies

Riechers, D. A. and Walter, F. and Carilli, C. L. and Knudsen, K. K. and Lo, K. Y. and Benford, D. J. and Staguhn, J. G. and Hunter, T. R. and Bertoldi, F. and Henkel, C. and Menten, K. M. and Weiss, A. and Yun, M. S. and Scoville, N. Z. (2006) Detecting Low-Order CO Emission from z ≳ 4 Quasar Host Galaxies. In: Galaxy Evolution across the Hubble Time. IAU Symposium Proceedings Series. No.235. Cambridge University Press , Cambridge, p. 423. ISBN 9780521863445.

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Molecular gas has now been detected in 15 z>2 QSOs. These detections are commonly obtained by observing high–J CO transitions due to their relatively high peak fluxes and observing frequencies in the millimeter atmospheric windows. However, only observations of the CO ground-state transition, CO(1–0), have the potential to trace the molecular gas at lower excitations, which may give a better estimate of the total molecular gas mass of high–z QSOs. Here we present first z>4 CO(1–0) observations obtained with the NRAO Green Bank Telescope and the MPIfR Effelsberg telescope (Riechers et al. 2006). With these two 100m telescopes, we detect the CO(1–0) transition in the high–redshift QSOs BR 1202-0725 (z = 4.7), PSS J2322+1944 (z = 4.1), and APM 08279+5255 (z = 3.9). We find that the CO/FIR luminosity ratios of these high-z sources follow the same trend as seen for low-z galaxies. Utilizing large velocity gradient (LVG) models based on previous results for higher–J CO transitions, we derive that all CO emission can be described by a single gas component and that all molecular gas appears to be concentrated in a compact nuclear region. We thus find no evidence for luminous, extended CO(1–0) components in the molecular gas reservoirs around our target quasars.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Riechers, D. A.0000-0001-9585-1462
Walter, F.0000-0003-4793-7880
Carilli, C. L.0000-0001-6647-3861
Knudsen, K. K.0000-0002-7821-8873
Benford, D. J.0000-0002-9884-4206
Staguhn, J. G.0000-0002-8437-0433
Hunter, T. R.0000-0001-6492-0090
Bertoldi, F.0000-0002-1707-1775
Menten, K. M.0000-0001-6459-0669
Weiss, A.0000-0003-4678-3939
Yun, M. S.0000-0001-7095-7543
Scoville, N. Z.0000-0002-0438-3323
Additional Information:© 2007 International Astronomical Union. D. R. acknowledges support from the Deutsche Forschungsgemeinschaft (DFG) Priority Programme 1177. C. C. acknowledges support from the Max-Planck-Gesellschaft and the Alexander von Humboldt-Stiftung through the Max-Planck-Forschungspreis.
Funding AgencyGrant Number
Deutsche Forschungsgemeinschaft (DFG)1177
Max Planck GesellschaftUNSPECIFIED
Alexander von Humboldt FoundationUNSPECIFIED
Max Planck ForschungspreisUNSPECIFIED
Subject Keywords:cosmology: observations, galaxies: ISM, galaxies: high-redshift, galaxies: formation, galaxies: starburst, galaxies: active
Series Name:IAU Symposium Proceedings Series
Issue or Number:235
Record Number:CaltechAUTHORS:20181211-084149249
Persistent URL:
Official Citation:Riechers, D., Walter, F., Carilli, C., Knudsen, K., Lo, K., Benford, D., . . . Scoville, N. (2006). Detecting Low-Order CO Emission from z ≳ 4 Quasar Host Galaxies. Proceedings of the International Astronomical Union, 2(S235), 423-423. doi:10.1017/S1743921306010507
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:91669
Deposited By: Tony Diaz
Deposited On:11 Dec 2018 17:36
Last Modified:16 Nov 2021 03:43

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