Sky reconstruction from transit visibilities: PAON-4 and Tianlai dish array. Issue 2 (8th July 2016)

• Record Type: Journal Article
• Authors: Zhang, Jiao; Ansari, Reza; Chen, Xuelei; Campagne, Jean-Eric; Magneville, Christophe; Wu, Fengquan
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 461:Issue 2(2016)
• Page Start: 1950
• Page End: 1966
• Publication Date: 2016-07-08
• Subjects: methods: data analysis -- methods: numerical -- techniques: interferometric -- cosmology: observations -- large-scale structure of Universe -- radio lines: galaxies; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stw1458
• Languages: English
• ISSNs: 0035-8711

Abstract

Abstract: The spherical harmonics m -mode decomposition is a powerful sky map reconstruction method suitable for radio interferometers operating in transit mode. It can be applied to various configurations, including dish arrays and cylinders. We describe the computation of the instrument response function, the point spread function, transfer function, the noise covariance matrix and noise power spectrum. The analysis in this paper is focused on dish arrays operating in transit mode. We show that arrays with regular spacing have more pronounced side lobes as well as structures in their noise power spectrum, compared to arrays with irregular spacing, specially in the north–south direction. A good knowledge of the noise power spectrum C noise (ℓ) is essential for intensity mapping experiments as non-uniform C noise (ℓ) is a potential problem for the measurement of the H i power spectrum. Different configurations have been studied to optimize the PAON-4 and Tianlai dish array layouts. We present their expected performance and their sensitivities to the 21-cm emission of the Milky Way and local extragalactic H i clumps.