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Table · dataset · 2024

M87 VLBA 43GHz images

Listed in IVOA Registry (Virtual Observatory)

Self-calibration methods with the CLEAN algorithm have been widely employed in Very Long Baseline Interferometry (VLBI) data processing in order to correct antenna-based amplitude and phase corruptions present in the data.

Description

However, human interaction during the conventional CLEAN self-calibration process can impose a strong effective prior, which in turn may produce artifacts within the final image and hinder the reproducibility of final results.

In this work, we aim to demonstrate a combined self-calibration and imaging method for VLBI data in a Bayesian inference framework. The method corrects for amplitude and phase gains for each antenna and polarization mode by inferring the temporal correlation of the gain solutions. We use Stokes I data of M87 taken with the Very Long Baseline Array (VLBA) at 43 GHz, pre-calibrated using the rPICARD CASA-based pipeline.

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For antenna-based gain calibration and imaging, we use the Bayesian imaging software resolve. To estimate gain and image uncertainties, we use a Variational Inference method. We obtain a high-resolution M87 Stokes I image at 43GHz in conjunction with antenna-based gain solutions using our Bayesian self-calibration and imaging method.

The core with counter-jet structure is better resolved, and extended jet emission is better described compared to the CLEAN reconstruction. Furthermore, uncertainty estimation of the image and antenna-based gains allows us to quantify the reliability of the result. Our Bayesian self-calibration and imaging pipeline is able to reconstruct robust and reproducible Stokes I images with gain solutions without the need of human interaction.

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Stated by source
Radio
Inferred from text
Image 75% · Imaging 75%
Provenance · 1 source records, 10 field assertions
SourceKeyLast seenRaw
IVOA Registry (Virtual Observatory)ivo://cds.vizier/j/a+a/690/a12914 d agoJSON v1
FieldAssertionExtractorEvidence
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concepts[modality].ivoa_waveband:radiosource · IVOA Registryconnector:ivoa_registry@1.0.0
concepts[modality].local:modality:imageenrichment · IVOA Registrykeyword-concept-rules@1.0.0title+description (75%)
concepts[modality].local:modality:imagingenrichment · IVOA Registrykeyword-concept-rules@1.0.0title+description (75%)
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updated_datesource · IVOA Registryconnector:ivoa_registry@1.0.0