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arXiv · 2407.00583

Closure invariants for polarised radio interferometric observations: a graph theoretical approach

Vinay Kumar·Rajaram Nityananda·Joseph Samuel
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Abstract

Aperture synthesis observations with full polarisation have long been used to study the magnetic fields of synchrotron emitting sources. Recently proposed closure invariants give us a powerful method for extracting information from measured visibilities which are corrupted by antenna and polarisation dependent gains. In this paper, a formalism developed earlier for complete graphs (where all visibilities are available) is extended to incomplete graphs. The formalism provides a complete and independent set of closure invariants from the measured visibilities in a general situation where not all visibilities are available. We then show in a simulated, quasi-realistic case that the invariants developed here contain usable information even in the presence of noise.

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Vinay Kumar, Rajaram Nityananda, Joseph Samuel. 2024-06-30. Closure invariants for polarised radio interferometric observations: a graph theoretical approach. https://arxiv.org/abs/2407.00583

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