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Foreground Subtraction and Signal reconstruction in redshifted 21cm Global Signal Experiments using Artificial Neural Networks

Published online by Cambridge University Press:  08 May 2018

Madhurima Choudhury  and
Abhirup Datta
Madhurima Choudhury
Affiliation:
Indian Institute of Technology, Indore Simrol, Khandwa Road, Indore, M.P., India email: [email protected]
Abhirup Datta
Affiliation:
Indian Institute of Technology, Indore Simrol, Khandwa Road, Indore, M.P., India email: [email protected]
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Abstract

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Observations of HI 21cm transition line is a promising probe into the Dark Ages and Epoch-of-Reionization. Detection of this redshifted 21cm signal is one of the key science goal for several upcoming low-frequency radio telescopes like HERA, SKA and DARE. Other global signal experiments include EDGES, LEDA, BIGHORNS, SCI-HI, SARAS. One of the major challenges for the detection of this signal is the accuracy of the foreground source removal. Several novel techniques have been explored already to remove bright foregrounds from both interferometric as well as total power experiments. Here, we present preliminary results from our investigation on application of ANN to detect 21cm global signal amidst bright galactic foreground. Following the formalism of representing the global 21cm signal by ’tanh’ model, this study finds that the global 21cm signal parameters can be accurately determined even in the presence of bright foregrounds represented by 3rd order log-polynomial or higher.

Keywords

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Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 12 , Symposium S333: Peering towards Cosmic Dawn , October 2017 , pp. 280 - 283
Copyright
Copyright © International Astronomical Union 2018 

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