APA
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Amiri, M., Bandura, K., Chakraborty, A., Dobbs, M., Fandino, M., Foreman, S., … Wulf, D. (2024). A Detection of Cosmological 21 cm Emission from CHIME in Cross-correlation with eBOSS Measurements of the Lyα Forest. Astrophysical Journal.
Chicago/Turabian
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Amiri, M., K. Bandura, Arnab Chakraborty, M. Dobbs, M. Fandino, Simon Foreman, Hyoyin Gan, et al. “A Detection of Cosmological 21 Cm Emission from CHIME in Cross-Correlation with EBOSS Measurements of the Lyα Forest.” Astrophysical Journal (2024).
MLA
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Amiri, M., et al. “A Detection of Cosmological 21 Cm Emission from CHIME in Cross-Correlation with EBOSS Measurements of the Lyα Forest.” Astrophysical Journal, 2024.
BibTeX Click to copy
@article{m2024a,
title = {A Detection of Cosmological 21 cm Emission from CHIME in Cross-correlation with eBOSS Measurements of the Lyα Forest},
year = {2024},
journal = {Astrophysical Journal},
author = {Amiri, M. and Bandura, K. and Chakraborty, Arnab and Dobbs, M. and Fandino, M. and Foreman, Simon and Gan, Hyoyin and Halpern, M. and Hill, A. and Hinshaw, Gary and Höfer, C. and Landecker, T. and Li, Zack and MacEachern, Joshua and Masui, K. and Mena-Parra, J. and Milutinovic, N. and Mirhosseini, A. and Newburgh, L. and Ordog, A. and Paul, Sourabh and Pen, U. and Pinsonneault-Marotte, T. and Reda, A. and Shaw, J. and Siegel, Seth R. and Vanderlinde, K. and Wang, Haochen and Wiebe, D. and Wulf, D.}
}
We report the detection of 21 cm emission at an average redshift z¯=2.3 in the cross-correlation of data from the Canadian Hydrogen Intensity Mapping Experiment (CHIME) with measurements of the Lyα forest from eBOSS. Data collected by CHIME over 88 days in the 400–500 MHz frequency band (1.8 < z < 2.5) are formed into maps of the sky and high-pass delay filtered to suppress the foreground power, corresponding to removing cosmological scales with k ∥ ≲ 0.13 Mpc−1 at the average redshift. Line-of-sight spectra to the eBOSS background quasar locations are extracted from the CHIME maps and combined with the Lyα forest flux transmission spectra to estimate the 21 cm–Lyα cross-correlation function. Fitting a simulation-derived template function to this measurement results in a 9σ detection significance. The coherent accumulation of the signal through cross-correlation is sufficient to enable a detection despite excess variance from foreground residuals ∼6–10 times brighter than the expected thermal noise level in the correlation function. These results are the highest-redshift measurement of 21 cm emission to date, and they set the stage for future 21 cm intensity mapping analyses at z > 1.8.