@article{d8be8b6cf61d484693658d7c599dbf6d,
title = "Probing Cosmic Reionization and Molecular Gas Growth with TIME",
abstract = "Line intensity mapping (LIM) provides a unique and powerful means to probe cosmic structures by measuring the aggregate line emission from all galaxies across redshift. The method is complementary to conventional galaxy redshift surveys that are object based and demand exquisite point-source sensitivity. The Tomographic Ionized-carbon Mapping Experiment (TIME) will measure the star formation rate during cosmic reionization by observing the redshifted [C ii] 158 μm line (6 ≲ z ≲ 9) in the LIM regime. TIME will simultaneously study the abundance of molecular gas during the era of peak star formation by observing the rotational CO lines emitted by galaxies at 0.5 ≲ z ≲ 2. We present the modeling framework that predicts the constraining power of TIME on a number of observables, including the line luminosity function and the auto- and cross-correlation power spectra, including synergies with external galaxy tracers. Based on an optimized survey strategy and fiducial model parameters informed by existing observations, we forecast constraints on physical quantities relevant to reionization and galaxy evolution, such as the escape fraction of ionizing photons during reionization, the faint-end slope of the galaxy luminosity function at high redshift, and the cosmic molecular gas density at cosmic noon. We discuss how these constraints can advance our understanding of cosmological galaxy evolution at the two distinct cosmic epochs for TIME, starting in 2021, and how they could be improved in future phases of the experiment.",
author = "G. Sun and Chang, {T. C.} and Uzgil, {B. D.} and Bock, {J. J.} and Bradford, {C. M.} and V. Butler and T. Caze-Cortes and Cheng, {Y. T.} and A. Cooray and Crites, {A. T.} and S. Hailey-Dunsheath and N. Emerson and C. Frez and Hoscheit, {B. L.} and J. Hunacek and Keenan, {R. P.} and Li, {C. T.} and P. Madonia and Marrone, {D. P.} and L. Moncelsi and C. Shiu and I. Trumper and A. Turner and A. Weber and Wei, {T. S.} and M. Zemcov",
note = "Funding Information: We would like to thank the anonymous referees for their comments that improved the manuscript. We are indebted to Lluis Mas-Ribas for helpful comments on an early version of the paper and to Lin Yan for discussion on the [C II] luminosity function measured from the ALPINE survey. We are also grateful to Garrett (Karto) Keating for compiling the observational constraints on molecular gas density. T.C.C. and G.S. acknowledge support from the JPL Strategic RandTD awards. A.C. acknowledges support from NSF AST-1313319 and 2015-2016 UCI Office of Research Seed Funding Award. D.P.M. and R.P.K. were supported by the National Science Foundation through CAREER grant AST-1653228. R.P.K. was supported by the National Science Foundation through Graduate Research Fellowship grant DGE-1746060. A.T.C. was supported by a KISS postdoctoral fellowship and a National Science Foundation Astronomy and Astrophysics Postdoctoral Fellowship under grant No. 1602677. This work is supported by National Science Foundation award number 1910598. 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 Publisher Copyright: {\textcopyright} 2021. The American Astronomical Society. All rights reserved.",
year = "2021",
month = jul,
day = "1",
doi = "10.3847/1538-4357/abfe62",
language = "English (US)",
volume = "915",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "1",
}