A Halo Model Approach to the 21 cm and Lyα Cross-correlation

Journal Article · Fri Sep 01 04:00:00 EDT 2017 · Astrophysical Journal

DOI:https://doi.org/10.3847/1538-4357/AA7FF1· OSTI ID:22875875

Feng, Chang; Cooray, Asantha ^[1]; Keating, Brian ^[2]

---

1. Department of Physics and Astronomy, University of California, Irvine, CA 92697 (United States)
2. Department of Physics, University of California, San Diego, CA 92093 (United States)

We present a halo-model-based approach to calculate the cross-correlation between 21 cm H i intensity fluctuations and Lyα emitters (LAE) during the epoch of reionization (EoR). Ionizing radiation around dark matter halos are modeled as bubbles with the size and growth determined based on the reionization photon production, among other physical parameters. The cross-correlation shows a clear negative-to-positive transition, associated with transition from ionized to neutral hydrogen in the intergalactic medium during EoR. The cross-correlation is subject to several foreground contaminants, including foreground radio point sources important for 21 cm experiments and low-z interloper emission lines, such as Hα, O iii, and O ii, for Lyα experiments. Our calculations show that by masking out high fluxes in the Lyα measurement, the correlated foreground contamination on the 21 cm–Lyα cross-correlation can be dramatically reduced. We forecast the detectability of 21 cm–Lyα cross-correlation at different redshifts and adopt a Fisher matrix approach to estimate uncertainties on the key EoR parameters that have not been well constrained by other observations of reionization. This halo-model-based approach enables us to explore the EoR parameter space rapidly for different 21 cm and Lyα experiments.

• OSTI ID: 22875875
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 846; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
CORRELATIONS
EMISSION
FLUCTUATIONS
HYDROGEN
IONIZATION
IONIZING RADIATIONS
LYMAN LINES
NONLUMINOUS MATTER
POINT SOURCES
RED SHIFT
SPACE
STARS
UNIVERSE