Foreground contamination in Lyα intensity mapping during the epoch of reoinization
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Date
2014
Authors
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Journal ISSN
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Publisher
IOP Science
Abstract
The intensity mapping of Lyα emission during the epoch of reionization will be contaminated by foreground
emission lines from lower redshifts. We calculate the mean intensity and the power spectrum of Lyα emission at
z ∼ 7 and estimate the uncertainties according to the relevant astrophysical processes. We find that the low-redshift
emission lines from 6563 Å Hα, 5007 Å [O iii], and 3727 Å [O ii] will be strong contaminants on the observed
Lyα power spectrum. We make use of both the star formation rate and luminosity functions to estimate the mean
intensity and power spectra of the three foreground lines at z ∼ 0.5 for Hα, z ∼ 0.9 for [O iii], and z ∼ 1.6 for
[O ii], as they will contaminate the Lyα emission at z ∼ 7. The [O ii] line is found to be the strongest. We analyze
the masking of the bright survey pixels with a foreground line above some line intensity threshold as a way to reduce
the contamination in an intensity mapping survey. We find that the foreground contamination can be neglected if
we remove pixels with fluxes above 1.4 × 10−20 W m−2
Description
Keywords
Large-scale structure of universe, Cosmology, Diffusion radiation
Citation
Gong, Y. et al. (2014) Foreground contamination in Lyα intensity mapping during the epoch of reoinization. The Astrophysics Journal, April, 785:72