H i intensity mapping: a single dish approach

By R. Battye, I. Browne, C. Dickinson, G. Heron, B. Maffei, A. Pourtsidou. 2012

168 citations recorded by the source corpus.

We discuss the detection of large-scale H I intensity fluctuations using a single dish approach with the ultimate objective of measuring the baryonic acoustic oscillations (BAO) and constraining the properties of dark energy. To characterize the signal we present 3D power spectra, 2D angular power spectra for individual redshift slices and also individual line-of-sight spectra computed using the S 3 simulated H I catalogue which is based on the Millennium Simulation. We consider optimal instrument design and survey strategies for a single dish observation at low and high redshift for a fixed sensitivity. For a survey corresponding to an instrument with T sys = 50 K, 50 feedhorns and 1 year of observations, we find that at low redshift (z ? 0.3), a resolution of ?40 arcmin and a survey of ?5000 deg 2 is close to optimal, whereas at higher redshift (z ? 0.9) a resolution of ?10 arcmin and ?500 deg 2 would be necessary - something which would be difficult to achieve cheaply using a single dish. Continuum foreground emission from the Galaxy and extragalactic radio sources are potentially a problem. In particular, we suggest that it could be that the dominant extragalactic foreground comes from the clustering of very weak sources. We assess its amplitude and discuss ways by which it might be mitigated. We then introduce our concept for a dedicated single dish telescope designed to detect BAO at low redshifts. It involves an underillumintated static ?40 m dish and a ?60 element receiver array held ?90 m above the underilluminated dish. Correlation receivers will be used with each main science beam referenced against an antenna pointing at one of the celestial poles for stability and control of systematics. We make sensitivity estimates for our proposed system and projections for the uncertainties on the power spectrum after 1 year of observations. We find that it is possible to measure the acoustic scale at z ? 0.3 with an accuracy ?2.4 per cent and that w can be measured to an accuracy of 16 per cent.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/f99fc2f4938c8985b668a1a56e833af9413798fc

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In Astronomy and Astrophysics

Citations in the corpus

LATE-TIME COSMOLOGY WITH 21 cm INTENSITY MAPPING EXPERIMENTS (2014, methodology): “One approach for H I instruments is that proposed by BINGO (Battye et al. 2013).”
Cosmology with Phase 1 of the Square Kilometre Array Red Book 2018: Technical specifications and performance forecasts (2018, methodology): “Upcoming experiments such as the recently built MeerKAT telescope, which will become part of SKA1-Mid, and the bespoke BINGO telescope (Battye et al. 2013) will play an important role in this process in the context of single-dish observations.”
An improved source-subtracted and destriped 408 MHz all-sky map (2014, methodology): “More recently, they have been used in simulations for HI intensity mapping experiments, both at moderate redshifts (Ansari et al. 2012; Battye et al. 2013; Wolz et al. 2014) and at high c© 2002 RAS ar X iv :1 41 1.”