首页|Application of Regularization Methods in the Sky Map Reconstruction of the Tianlai Cylinder Pathfinder Array

Application of Regularization Methods in the Sky Map Reconstruction of the Tianlai Cylinder Pathfinder Array

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The Tianlai cylinder pathfinder is a radio interferometer array to test 21 cm intensity mapping techniques in the post-reionization era.It works in passive drift scan mode to survey the sky visible in the northern hemisphere.To deal with the large instantaneous field of view and the spherical sky,we decompose the drift scan data into m-modes,which are linearly related to the sky intensity.The sky map is reconstructed by solving the linear interferometer equations.Due to incomplete uv coverage of the interferometer baselines,this inverse problem is usually ill-posed,and regularization method is needed for its solution.In this paper,we use simulation to investigate two frequently used regularization methods,the Truncated Singular Value Decomposition(TSVD),and the Tikhonov regularization techniques.Choosing the regularization parameter is very important for its application.We employ the generalized cross validation method and the L-curve method to determine the optimal value.We compare the resulting maps obtained with the different regularization methods,and for the different parameters derived using the different criteria.While both methods can yield good maps for a range of regularization parameters,in the Tikhonov method the suppression of noisy modes are more gradually applied,produce more smooth maps which avoids some visual artefacts in the maps generated with the TSVD method.

techniques:interferometricmethods:numericalcosmology:observationsradio continuum:general

Kaifeng Yu、Shifan Zuo、Fengquan Wu、Yougang Wang、Xuelei Chen

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National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China

Key Laboratory of Radio Astronomy and Technology,Chinese Academy of Sciences,Beijing 100101,China

School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China

Key Laboratory of Cosmology and Astrophysics(Liaoning)& College of Sciences,Northeastern University,Shenyang 110819,China

Center of High Energy Physics,Peking University,Beijing 100871,China

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National SKA Program of ChinaNational SKA Program of China国家自然科学基金国家自然科学基金国家自然科学基金

2022SKA01101002022SKA0110101122030611227307012303004

2024

10.1088/1674-4527/ad1223

天文和天体物理学研究
中国科学院国家天文台

天文和天体物理学研究

CSTPCD
影响因子：0.406
ISSN：1674-4527
年,卷(期)：2024.24(2)
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