Estimating the feasibility of 21cm-Lyα synergies using the hydrogen Epoch of Reionization array

Tyler A. Cox, Daniel C. Jacobs, Steven G. Murray

Research output: Contribution to journalArticlepeer-review

Abstract

Cross-correlating 21cm and Lyα intensity maps of the Epoch of Reionization promises to be a powerful tool for exploring the properties of the first galaxies. Next-generation intensity mapping experiments such as the Hydrogen Epoch of Reionization Array (HERA) and SPHEREx will individually probe reionization through the power spectra of the 21cm and Lyα lines respectively, but will be limited by bright foregrounds and instrumental systematics. Cross-correlating these measurements could reduce systematics, potentially tightening constraints on the inferred astrophysical parameters. In this study, we present forecasts of cross-correlation taking into account the effects of exact uv-sampling and foreground filtering to estimate the feasibility of HERAxSPHEREx making a detection of the 21cm-Lyα cross-power spectrum. We also project the sensitivity of a cross-power spectrum between HERA and the proposed next-generation Cosmic Dawn Intensity Mapper. By isolating the sources of uncertainty, we explore the impacts of experimental limitations such as foreground filtering and Lyα thermal noise uncertainty have on making a detection of the cross-power spectrum. We then implement this strategy in a simulation of the cross-power spectrum and observational error to identify redshifts where fiducial 21cmFAST models predict the highest signal-to-noise detection (z ∼8). We conclude that detection of the SPHEREx-HERA cross-correlation will require an optimistic level of 21cm foreground filtering, as well as deeper thermal noise integrations due to a lack of overlapping sensitive modes but for CDIM with its larger range of scales and lower noise forecast detection levels, may be possible even with stricter 21cm foreground filtering.

Original languageEnglish (US)
Pages (from-to)792-801
Number of pages10
JournalMonthly Notices of the Royal Astronomical Society
Volume512
Issue number1
DOIs
StatePublished - May 1 2022

Keywords

  • cosmology: dark ages, reionization, first stars
  • galaxies: high-redshift
  • instrumentation: interferometers

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'Estimating the feasibility of 21cm-Lyα synergies using the hydrogen Epoch of Reionization array'. Together they form a unique fingerprint.

Cite this