SYMBA: An end-to-end VLBI synthetic data generation pipeline: Simulating Event Horizon Telescope observations of M 87

dc.contributorAalto-yliopistofi
dc.contributorAalto Universityen
dc.contributor.authorRamakrishnan, Venkatesshen_US
dc.contributor.authorSavolainen, Tuomasen_US
dc.contributor.authorZhao, Shanshanen_US
dc.contributor.author, Event Horizon Telescope Collaboraten_US
dc.contributor.departmentDepartment of Electronics and Nanoengineeringen
dc.contributor.departmentMetsähovi Radio Observatoryen
dc.contributor.groupauthorAnne Lähteenmäki Groupen
dc.contributor.organizationRadboud University Nijmegenen_US
dc.contributor.organizationUniversidad de Concepciónen_US
dc.date.accessioned2020-04-28T06:58:27Z
dc.date.available2020-04-28T06:58:27Z
dc.date.issued2020-04-01en_US
dc.description.abstractContext. Realistic synthetic observations of theoretical source models are essential for our understanding of real observational data. In using synthetic data, one can verify the extent to which source parameters can be recovered and evaluate how various data corruption effects can be calibrated. These studies are the most important when proposing observations of new sources, in the characterization of the capabilities of new or upgraded instruments, and when verifying model-based theoretical predictions in a direct comparison with observational data. Aims. We present the SYnthetic Measurement creator for long Baseline Arrays (SYMBA), a novel synthetic data generation pipeline for Very Long Baseline Interferometry (VLBI) observations. SYMBA takes into account several realistic atmospheric, instrumental, and calibration effects. Methods. We used SYMBA to create synthetic observations for the Event Horizon Telescope (EHT), a millimetre VLBI array, which has recently captured the first image of a black hole shadow. After testing SYMBA with simple source and corruption models, we study the importance of including all corruption and calibration effects, compared to the addition of thermal noise only. Using synthetic data based on two example general relativistic magnetohydrodynamics (GRMHD) model images of M 87, we performed case studies to assess the image quality that can be obtained with the current and future EHT array for different weather conditions. Results. Our synthetic observations show that the effects of atmospheric and instrumental corruptions on the measured visibilities are significant. Despite these effects, we demonstrate how the overall structure of our GRMHD source models can be recovered robustly with the EHT2017 array after performing calibration steps, which include fringe fitting, a priori amplitude and network calibration, and self-calibration. With the planned addition of new stations to the EHT array in the coming years, images could be reconstructed with higher angular resolution and dynamic range. In our case study, these improvements allowed for a distinction between a thermal and a non-thermal GRMHD model based on salient features in reconstructed images.en
dc.description.versionPeer revieweden
dc.format.mimetypeapplication/pdfen_US
dc.identifier.citationRamakrishnan, V, Savolainen, T, Zhao, S & Event Horizon Telescope Collaboration 2020, ' SYMBA: An end-to-end VLBI synthetic data generation pipeline: Simulating Event Horizon Telescope observations of M 87 ', Astronomy and Astrophysics, vol. 636, 5 . https://doi.org/10.1051/0004-6361/201936622en
dc.identifier.doi10.1051/0004-6361/201936622en_US
dc.identifier.issn0004-6361
dc.identifier.issn1432-0746
dc.identifier.otherPURE UUID: b3dfb4ad-069e-4e33-8122-2e030f4344e7en_US
dc.identifier.otherPURE ITEMURL: https://research.aalto.fi/en/publications/b3dfb4ad-069e-4e33-8122-2e030f4344e7en_US
dc.identifier.otherPURE LINK: http://www.scopus.com/inward/record.url?scp=85083330600&partnerID=8YFLogxKen_US
dc.identifier.otherPURE FILEURL: https://research.aalto.fi/files/42557021/Savolainen_Symba_Aanda.pdfen_US
dc.identifier.urihttps://aaltodoc.aalto.fi/handle/123456789/43911
dc.identifier.urnURN:NBN:fi:aalto-202004282905
dc.language.isoenen
dc.publisherEDP SCIENCES
dc.relation.ispartofseriesAstronomy and Astrophysicsen
dc.relation.ispartofseriesVolume 636en
dc.rightsopenAccessen
dc.subject.keywordAtmospheric effectsen_US
dc.subject.keywordBlack hole physicsen_US
dc.subject.keywordGalaxies: nucleien_US
dc.subject.keywordTechniques: high angular resolutionen_US
dc.subject.keywordTechniques: interferometricen_US
dc.subject.keywordTelescopesen_US
dc.titleSYMBA: An end-to-end VLBI synthetic data generation pipeline: Simulating Event Horizon Telescope observations of M 87en
dc.typeA1 Alkuperäisartikkeli tieteellisessä aikakauslehdessäfi
dc.type.versionpublishedVersion

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