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Intensity Mapping of the [C II] Fine Structure Line During the Epoch of Reionization

Gong, Yan and Cooray, Asantha and Silva, Marta and Santos, Mario G. and Bock, James and Bradford, C. Matt and Zemcov, Michael (2012) Intensity Mapping of the [C II] Fine Structure Line During the Epoch of Reionization. Astrophysical Journal, 745 (1). Art. No. 49. ISSN 0004-637X. doi:10.1088/0004-637X/745/1/49.

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The atomic C II fine-structure line is one of the brightest lines in a typical star-forming galaxy spectrum with a luminosity ~0.1%-1% of the bolometric luminosity. It is potentially a reliable tracer of the dense gas distribution at high redshifts and could provide an additional probe to the era of reionization. By taking into account the spontaneous, stimulated, and collisional emission of the C II line, we calculate the spin temperature and the mean intensity as a function of the redshift. When averaged over a cosmologically large volume, we find that the C II emission from ionized carbon in individual galaxies is larger than the signal generated by carbon in the intergalactic medium. Assuming that the C II luminosity is proportional to the carbon mass in dark matter halos, we also compute the power spectrum of the C II line intensity at various redshifts. In order to avoid the contamination from CO rotational lines at low redshift when targeting a C II survey at high redshifts, we propose the cross-correlation of C II and 21 cm line emission from high redshifts. To explore the detectability of the C II signal from reionization, we also evaluate the expected errors on the C II power spectrum and C II-21 cm cross power spectrum based on the design of the future millimeter surveys. We note that the C II-21 cm cross power spectrum contains interesting features that capture physics during reionization, including the ionized bubble sizes and the mean ionization fraction, which are challenging to measure from 21 cm data alone. We propose an instrumental concept for the reionization C II experiment targeting the frequency range of ~200-300 GHz with 1, 3, and 10 m apertures and a bolometric spectrometer array with 64 independent spectral pixels with about 20,000 bolometers.

Item Type:Article
Related URLs:
URLURL TypeDescription
Cooray, Asantha0000-0002-3892-0190
Santos, Mario G.0000-0003-3892-3073
Bock, James0000-0002-5710-5212
Bradford, C. Matt0000-0001-5261-7094
Zemcov, Michael0000-0001-8253-1451
Additional Information:© 2012 American Astronomical Society. Received 2011 July 18; accepted 2011 October 20; published 2011 December 28. We thank participants of the Keck Institute for Space Studies’ (KISS) Billion Years workshop for helpful discussions. This work was supported by NSF CAREER AST-0645427 and NASA NNX10AD42G at UCI. M.G.S. and M.B.S. acknowledge support from FCT-Portugal under grant PTDC/FIS/ 100170/2008.
Group:TAPIR, Keck Institute for Space Studies
Funding AgencyGrant Number
Fundação para a Ciência e a Tecnologia (FCT)PTDC/FIS/100170/2008
Subject Keywords:cosmology: theory; diffuse radiation; intergalactic medium; large-scale structure of universe
Issue or Number:1
Record Number:CaltechAUTHORS:20120403-080450129
Persistent URL:
Official Citation: Intensity Mapping of the [C II] Fine Structure Line during the Epoch of Reionization Yan Gong et al. 2012 ApJ 745 49
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:29945
Deposited By: Ruth Sustaita
Deposited On:03 Apr 2012 15:26
Last Modified:09 Nov 2021 19:33

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