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Cosmic Near-infrared Background Tomography with SPHEREx Using Galaxy Cross-correlations

Cheng, Yun-Ting and Chang, Tzu-Ching (2022) Cosmic Near-infrared Background Tomography with SPHEREx Using Galaxy Cross-correlations. Astrophysical Journal, 925 (2). Art. No. 136. ISSN 0004-637X. doi:10.3847/1538-4357/ac3aee.

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The extragalactic background light (EBL) consists of integrated light from all sources of emission throughout the history of the universe. At near-infrared wavelengths, the EBL is dominated by stellar emission across cosmic time; however, the spectral and redshift information of the emitting sources is entangled and cannot be directly measured by absolute photometry or fluctuation measurements. Cross-correlating near-infrared maps with tracers of known redshift enables EBL redshift tomography, as EBL emission will only correlate with external tracers from the same redshift. Here, we forecast the sensitivity of probing the EBL spectral energy distribution as a function of redshift by cross-correlating the upcoming near-infrared spectro-imaging survey, SPHEREx, with several current and future galaxy redshift surveys. Using a model galaxy luminosity function, we estimate the cross power spectrum clustering amplitude on large scales, and forecast that the near-infrared EBL spectrum can be detected tomographically out to z ∼ 6. We also predict a high-significance measurement (∼10²–10⁴σ) of the small-scale cross power spectrum out to z ∼ 10. The amplitudes of the large-scale cross power spectra can constrain the cosmic evolution of the stellar synthesis process through both continuum and the line emission, while on the nonlinear and Poisson noise scales, the high-sensitivity measurements can probe the mean spectra associated with the tracer population across redshift.

Item Type:Article
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URLURL TypeDescription Paper
Cheng, Yun-Ting0000-0002-5437-0504
Chang, Tzu-Ching0000-0001-5929-4187
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 2021 September 21; revised 2021 November 15; accepted 2021 November 16; published 2022 February 1. We are grateful to Jamie Bock, Yi-Kuan Chiang, Emmanuel Schann, Olivier Doré, Richard Feder, Lluis Mas-Ribas, Daniel Masters, and Rogier Windhorst for helpful discussions and comments on the draft. We are in debt to Lluis Mas-Ribas for providing the quasar spectrum template, Emmanuel Schann for suggesting the trispectrum correction, and Steven Finkelstein for providing the Roman Space Telescope High Latitude Survey galaxy number count estimates. Y.-T.C. acknowledges support by the Ministry of Education, Taiwan through the Taiwan-Caltech Scholarship. T.-C.C. acknowledges support from the JPL Strategic R&TD awards. Part of this work was done at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.
Funding AgencyGrant Number
Ministry of Education (Taipei)UNSPECIFIED
JPL Internal Research and Technology Development ProgramUNSPECIFIED
Subject Keywords:Large-scale structure of the universe; Cosmology; Cosmic background radiation
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Large-scale structure of the universe (902); Cosmology (343); Cosmic background radiation (317)
Record Number:CaltechAUTHORS:20220203-315512000
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Official Citation:Yun-Ting Cheng and Tzu-Ching Chang 2022 ApJ 925 136
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:113240
Deposited By: George Porter
Deposited On:03 Feb 2022 20:48
Last Modified:03 Feb 2022 20:48

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