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Intensity Mapping with Carbon Monoxide Emission Lines and the Redshifted 21 cm Line

Lidz, Adam and Furlanetto, Steven R. and Oh, S. Peng and Aguirre, James and Chang, Tzu-Ching and Doré, Olivier and Pritchard, Jonathan R. (2011) Intensity Mapping with Carbon Monoxide Emission Lines and the Redshifted 21 cm Line. Astrophysical Journal, 741 (2). p. 70. ISSN 0004-637X.

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We quantify the prospects for using emission lines from rotational transitions of the CO molecule to perform an "intensity mapping" observation at high redshift during the Epoch of Reionization (EoR). The aim of CO intensity mapping is to observe the combined CO emission from many unresolved galaxies, to measure the spatial fluctuations in this emission, and to use this as a tracer of large-scale structure at very early times in the history of our universe. This measurement would help determine the properties of molecular clouds—the sites of star formation—in the very galaxies that reionize the universe. We further consider the possibility of cross-correlating CO intensity maps with future observations of the redshifted 21 cm line. The cross spectrum is less sensitive to foreground contamination than the auto power spectra, and can therefore help confirm the high-redshift origin of each signal. Furthermore, the cross spectrum measurement would help extract key information about the EoR, especially regarding the size distribution of ionized regions. We discuss uncertainties in predicting the CO signal at high redshift, and discuss strategies for improving these predictions. Under favorable assumptions and feasible specifications for a CO survey mapping the CO(2-1) and CO(1-0) lines, the power spectrum of CO emission fluctuations and its cross spectrum with future 21 cm measurements from the Murchison Widefield Array are detectable at high significance.

Item Type:Article
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URLURL TypeDescription
Furlanetto, Steven R.0000-0002-0658-1243
Doré, Olivier0000-0002-5009-7563
Additional Information:© 2011 American Astronomical Society. Received 2011 April 25; accepted 2011 August 1; published 2011 October 18. We thank Matt McQuinn for providing the reionization simulations used in this analysis and for comments on a draft. We are also grateful to Mark Krumholz and the anonymous referee for helpful remarks that have improved this paper. This work was initiated at the summer 2010 Aspen 21 cm cosmology meeting. This meeting and a subsequent meeting at the Keck Institute for Space Sciences helped fuel this work, and we acknowledge useful conversations with the participants of these meetings. We are especially grateful to Judd Bowman as a co-organizer of both of these meetings. S.R.F. was partially supported by the David and Lucile Packard Foundation, by the Alfred P. Sloan Foundation, and by NASA through the LUNAR program. The LUNAR consortium (, headquartered at the University of Colorado, is funded by the NASA Lunar Science Institute (via Cooperative Agreement NNA09DB30A) to investigate concepts for astrophysical observatories on the Moon. S.P.O. acknowledges NSF grant AST 0908480 for support. Part of the research described in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Funding AgencyGrant Number
David and Lucile Packard FoundationUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Subject Keywords:cosmology: theory; intergalactic medium; large-scale structure of universe
Issue or Number:2
Record Number:CaltechAUTHORS:20120127-095735206
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Official Citation:Intensity Mapping with Carbon Monoxide Emission Lines and the Redshifted 21 cm Line Adam Lidz et al. 2011 ApJ 741 70
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:28996
Deposited By: Jason Perez
Deposited On:30 Jan 2012 15:45
Last Modified:09 Mar 2020 13:18

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