Impact of 1/f noise on cosmological parameter constraints for SKA intensity mapping

T Chen, R A Battye, A A Costa, C Dickinson, S E Harper

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We investigate the impact of 1/f noise on cosmology for an intensity mapping survey with SKA1-MID Band 1 and Band 2. We use a Fisher matrix approach to forecast constraints on cosmological parameters under the influence of 1/f noise, adopting a semi-empirical model from an earlier work, which results from the residual 1/f noise spectrum after applying a component separation algorithm to remove smooth spectral components. Without 1/f noise, the projected constraints are 4 per cent on w0, 1 per cent on h, 2 per cent on bH I using Band 1+Planck, and 3 per cent on w0, 0.5 per cent on h, 2 per cent on bH I using Band 2+Planck. A representative baseline 1/f noise degrades these constraints by a factor of ∼1.5 for Band 1+Planck, and ∼1.2 for Band 2+Planck. On the power spectrum measurement, higher redshift and smaller scales are more affected by 1/f noise, with minimal contamination comes from z ≲ 1 and ℓ ≲ 100. Subject to the specific scan strategy of the adopted 1/f noise model, one prefers a correlation in frequency with minimized spectral slope, a low knee frequency, and a large telescope slew speed in order to reduce its impact.
Original languageUndefined
JournalMonthly Notices of the Royal Astronomical Society
Early online date26 Nov 2019
Publication statusPublished - 21 Jan 2020

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