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Cosmological Constraints on the Global Star Formation Law of Galaxies: Insights from Baryon Acoustic Oscillation Intensity Mapping

Sun, Guochao (2022) Cosmological Constraints on the Global Star Formation Law of Galaxies: Insights from Baryon Acoustic Oscillation Intensity Mapping. Astrophysical Journal Letters, 931 (2). Art. No. L29. ISSN 2041-8205. doi:10.3847/2041-8213/ac7138.

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Originally proposed as a cosmological probe of the large-scale structure, line intensity mapping (LIM) also offers a unique window into the astrophysics of galaxy evolution. Adding to the astrophysical explorations of the LIM technique that have traditionally focused on small, nonlinear scales, we present a novel method to study the global star formation law using forthcoming data from large-scale baryonic acoustic oscillation (BAO) intensity mapping. Using the amplitude of the percent-level but scale-dependent bias induced by baryon fraction fluctuations on BAO scales, we show that combining auto- and cross-correlation power spectra of two (or more) LIM signals allows to probe the star formation law power index N. We examine the prospect for mapping Hα and [O iii] lines across all scales, especially where imprints of the baryon fraction deviation exist, with space missions like SPHEREx. We show that although SPHEREx may only marginally probe N by accessing a modest number of large-scale modes in its 200 deg² deep survey, future infrared all-sky surveys reaching a comparable depth with an improved spectral resolution (R ≳ 400) are likely to constrain N to a precision of 10%–30%, sufficient for distinguishing models with varying feedback assumptions, out to z ∼ 4 using BAO intensity mapping. Leveraging this effect, large, cosmic-variance-limited LIM surveys in the far future can scrutinize the physical connection between galaxy evolution and the large-scale cosmological environment, while performing stringent tests of the standard cosmological model.

Item Type:Article
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URLURL TypeDescription Paper
Sun, Guochao0000-0003-4070-497X
Additional Information:© 2022. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2022 April 5; revised 2022 May 12; accepted 2022 May 19; published 2022 May 31. We thank Jordan Mirocha, Tzu-Ching Chang, Lluís Mas-Ribas, and Jamie Bock for helpful conversations and comments, as well as the anonymous referee for comments that improved the manuscript. We acknowledge the support from the JPL R&TD strategic initiative grant on line intensity mapping.
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JPL Research and Technology Development FundUNSPECIFIED
Subject Keywords:Observational cosmology; Baryon acoustic oscillations; Large-scale structure of the universe; Galaxy evolution; Star formation
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Observational cosmology (1146); Baryon acoustic oscillations (138); Large-scale structure of the universe (902); Galaxy evolution (594); Star formation (1569)
Record Number:CaltechAUTHORS:20220725-156877000
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Official Citation:Guochao Sun 2022 ApJL 931 L29
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:115835
Deposited By: George Porter
Deposited On:27 Jul 2022 16:45
Last Modified:27 Jul 2022 16:45

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