Journal article

Foreground modelling via Gaussian process regression: An application to HERA data

A Ghosh, F Mertens, G Bernardi, MG Santos, NS Kern, CL Carilli, TL Grobler, LVE Koopmans, DC Jacobs, A Liu, AR Parsons, MF Morales, JE Aguirre, JS Dillon, BJ Hazelton, OM Smirnov, BK Gehlot, S Matika, P Alexander, ZS Ali Show all

Monthly Notices of the Royal Astronomical Society | Royal Astronomical Society | Published : 2020

Abstract

The key challenge in the observation of the redshifted 21-cm signal from cosmic reionization is its separation from the much brighter foreground emission. Such separation relies on the different spectral properties of the two components, although, in real life, the foreground intrinsic spectrum is often corrupted by the instrumental response, inducing systematic effects that can further jeopardize the measurement of the 21-cm signal. In this paper, we use Gaussian Process Regression to model both foreground emission and instrumental systematics in ∼2 h of data from the Hydrogen Epoch of Reionization Array. We find that a simple co-variance model with three components matches the data well, g..

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University of Melbourne Researchers

Grants

Awarded by National Science Foundation


Awarded by National Research Foundation of South Africa


Awarded by Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D)


Awarded by NWO-NRF Exchange Programme in Astronomy and Enabling technologies in Astronomy (NWO)


Awarded by Newton Fund


Awarded by National Research Foundation


Awarded by INAF PRIN-SKA 2017 project (FORECaST)


Awarded by Ministero degli Affari Esteri e della Cooperazione Internazionale - Direzione Generale per la Promozione del Sistema Paese Progetto di Grande Rilevanza


Funding Acknowledgements

We thank the anonymous referee and the editors for their useful comments and suggestions. This material is based upon work supported by the National Science Foundation under grant nos. 1636646 and 1836019 and institutional support from the HERA collaboration partners. This work is funded in part by the Gordon and Betty Moore Foundation and the National Research Foundation of South Africa (grants nos. 103424 and 113121). HERA is hosted by the South African Radio Astronomy Observatory (SARAO), which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. Parts of this research were supported by the Australian Research Council Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D), through project number CE170100013. AG would like to thank SARAO for support through SKA postdoctoral fellowship, 2016. AG would also like to thank Dr. Sushanta Kumar Mondal for editing some of the figures. FGM and LVEK would like to acknowledge support from a SKA-NL Roadmap grant from the Dutch ministry of OCW. LVEK, FGM, and BG also acknowledge support by an NWO-NRF Exchange Programme in Astronomy and Enabling technologies in Astronomy (NWO grant no. 629.003.021). GB acknowledges support from the Royal Society and the Newton Fund under grant NA150184. MGS acknowledges support from the SARAO and the National Research Foundation (grant no. 84156). GB acknowledges funding from the INAF PRIN-SKA 2017 project 1.05.01.88.04 (FORECaST). We acknowledge the support from the Ministero degli Affari Esteri e della Cooperazione Internazionale - Direzione Generale per la Promozione del Sistema Paese Progetto di Grande Rilevanza ZA 18GR02. AL acknowledges support from the New Frontiers in Research Fund Exploration grant program, a Natural Sciences and Engineering Research Council of Canada Discovery Grant and a Discovery Launch Supplement, the Sloan Research Fellowship, as well as the Canadian Institute for Advanced Research Azrieli Global Scholars program. We acknowledge the HERA staff who made these observations possible.