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The 21-cm signature of the first stars during the Lyman–Werner feedback era

Fialkov, Anastasia and Barkana, Rennan and Visbal, Eli and Tseliakhovich, Dmitriy and Hirata, Christopher M. (2013) The 21-cm signature of the first stars during the Lyman–Werner feedback era. Monthly Notices of the Royal Astronomical Society, 432 (4). pp. 2909-2916. ISSN 0035-8711. doi:10.1093/mnras/stt650.

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The formation of the first stars is an exciting frontier area in astronomy. Early redshifts (z ∼ 20) have become observationally promising as a result of a recently recognized effect of a supersonic relative velocity between the dark matter and gas. This effect produces prominent structure on 100 comoving Mpc scales, which makes it much more feasible to detect 21-cm fluctuations from the epoch of first heating. We use semi-numerical hybrid methods to follow for the first time the joint evolution of the X-ray and Lyman–Werner radiative backgrounds, including the effect of the supersonic streaming velocity on the cosmic distribution of stars. We incorporate self-consistently the negative feedback on star formation induced by the Lyman–Werner radiation, which dissociates molecular hydrogen and thus suppresses gas cooling. We find that the feedback delays the X-ray heating transition by Δz ∼ 2, but leaves a promisingly large fluctuation signal over a broad redshift range. The large-scale power spectrum is predicted to reach a maximal signal-to-noise ratio of S/N ∼ 3–4 at z ∼ 18 (for a projected first-generation instrument), with S/N >1 out to z ∼ 22–23. We hope to stimulate additional numerical simulations as well as observational efforts focused on the epoch prior to cosmic reionization.

Item Type:Article
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URLURL TypeDescription Paper
Hirata, Christopher M.0000-0002-2951-4932
Additional Information:© 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. Accepted 2013 April 15; Received 2013 April 14; In original form 2012 August 30. First published online: May 9, 2013. We are most grateful to Zoltan Haiman for supplying us with the atomic data on the Lyman–Werner absorption lines. This work was supported by Israel Science Foundation grant 823/09. AF was also supported by European Research Council grant 203247.
Funding AgencyGrant Number
Israel Science Foundation823/09
European Research Council (ERC)203247
Subject Keywords:galaxies: formation; galaxies: high-redshift; intergalactic medium; cosmology: theory
Issue or Number:4
Record Number:CaltechAUTHORS:20130807-131646764
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:39806
Deposited On:07 Aug 2013 21:55
Last Modified:09 Nov 2021 23:47

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