Demonstration of polarisation calibration with the LBA on Selected AGNs

Thanapol Chanapote, Richard Dodson, Maria Rioja, Kitiyanee Asanok, Jamie Stevens, Ivan Marti-Vidal

Research output: Contribution to journalArticle

Abstract

We present here the results from a full polarisation study, an important VLBI capability, of a selected set of bright Active Galactic Nuclei (AGNs), along with the steps required to fully calibrate the Australian Long Baseline Array. We compare strategies for high-precision polarisation measurements using two polarisation correction methods: (1) Linear model and (2) Ellipticity-Orientation model and two data-recording techniques: recording (1) nominally circular polarisation at all stations and (2) mixed polarisation, where all but one station record circular polarisation and the other recorded linear polarisation. The latter is corrected post-correlation. We explored these possible solution to discover which will best accommodate the heterogeneous nature of the Australian Long Baseline Array without impacting on the science results. The targets, all compact and of low polarisation fraction, allow us to compare multiple independent solutions for polarisation characteristics. The results show that the agreement between the two polarisation correction models is excellent. However, the values from Mopra with nominally circular polarisation are larger than would be acceptable. However, we also demonstrate that recording mixed polarisation modes and correcting post-correlation provide a high quality polarisation product. We report on the detailed tests of these strategies and assess that the array is ready for full polarisation operation.

Original languageEnglish
Article number013
Number of pages21
JournalPublications of the Astronomical Society of Australia
Volume36
DOIs
Publication statusPublished - 15 Mar 2019

Cite this

Chanapote, Thanapol ; Dodson, Richard ; Rioja, Maria ; Asanok, Kitiyanee ; Stevens, Jamie ; Marti-Vidal, Ivan. / Demonstration of polarisation calibration with the LBA on Selected AGNs. In: Publications of the Astronomical Society of Australia. 2019 ; Vol. 36.
@article{c37d4ae4875942d4b400ebc2d9821a2f,
title = "Demonstration of polarisation calibration with the LBA on Selected AGNs",
abstract = "We present here the results from a full polarisation study, an important VLBI capability, of a selected set of bright Active Galactic Nuclei (AGNs), along with the steps required to fully calibrate the Australian Long Baseline Array. We compare strategies for high-precision polarisation measurements using two polarisation correction methods: (1) Linear model and (2) Ellipticity-Orientation model and two data-recording techniques: recording (1) nominally circular polarisation at all stations and (2) mixed polarisation, where all but one station record circular polarisation and the other recorded linear polarisation. The latter is corrected post-correlation. We explored these possible solution to discover which will best accommodate the heterogeneous nature of the Australian Long Baseline Array without impacting on the science results. The targets, all compact and of low polarisation fraction, allow us to compare multiple independent solutions for polarisation characteristics. The results show that the agreement between the two polarisation correction models is excellent. However, the values from Mopra with nominally circular polarisation are larger than would be acceptable. However, we also demonstrate that recording mixed polarisation modes and correcting post-correlation provide a high quality polarisation product. We report on the detailed tests of these strategies and assess that the array is ready for full polarisation operation.",
keywords = "polarisation methods: data analysis",
author = "Thanapol Chanapote and Richard Dodson and Maria Rioja and Kitiyanee Asanok and Jamie Stevens and Ivan Marti-Vidal",
year = "2019",
month = "3",
day = "15",
doi = "10.1017/pasa.2019.3",
language = "English",
volume = "36",
journal = "Publications of the Astronomincal Society of Australia (PASA)",
issn = "1323-3580",
publisher = "Cambridge University Press",

}

Demonstration of polarisation calibration with the LBA on Selected AGNs. / Chanapote, Thanapol; Dodson, Richard; Rioja, Maria; Asanok, Kitiyanee; Stevens, Jamie; Marti-Vidal, Ivan.

In: Publications of the Astronomical Society of Australia, Vol. 36, 013, 15.03.2019.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Demonstration of polarisation calibration with the LBA on Selected AGNs

AU - Chanapote, Thanapol

AU - Dodson, Richard

AU - Rioja, Maria

AU - Asanok, Kitiyanee

AU - Stevens, Jamie

AU - Marti-Vidal, Ivan

PY - 2019/3/15

Y1 - 2019/3/15

N2 - We present here the results from a full polarisation study, an important VLBI capability, of a selected set of bright Active Galactic Nuclei (AGNs), along with the steps required to fully calibrate the Australian Long Baseline Array. We compare strategies for high-precision polarisation measurements using two polarisation correction methods: (1) Linear model and (2) Ellipticity-Orientation model and two data-recording techniques: recording (1) nominally circular polarisation at all stations and (2) mixed polarisation, where all but one station record circular polarisation and the other recorded linear polarisation. The latter is corrected post-correlation. We explored these possible solution to discover which will best accommodate the heterogeneous nature of the Australian Long Baseline Array without impacting on the science results. The targets, all compact and of low polarisation fraction, allow us to compare multiple independent solutions for polarisation characteristics. The results show that the agreement between the two polarisation correction models is excellent. However, the values from Mopra with nominally circular polarisation are larger than would be acceptable. However, we also demonstrate that recording mixed polarisation modes and correcting post-correlation provide a high quality polarisation product. We report on the detailed tests of these strategies and assess that the array is ready for full polarisation operation.

AB - We present here the results from a full polarisation study, an important VLBI capability, of a selected set of bright Active Galactic Nuclei (AGNs), along with the steps required to fully calibrate the Australian Long Baseline Array. We compare strategies for high-precision polarisation measurements using two polarisation correction methods: (1) Linear model and (2) Ellipticity-Orientation model and two data-recording techniques: recording (1) nominally circular polarisation at all stations and (2) mixed polarisation, where all but one station record circular polarisation and the other recorded linear polarisation. The latter is corrected post-correlation. We explored these possible solution to discover which will best accommodate the heterogeneous nature of the Australian Long Baseline Array without impacting on the science results. The targets, all compact and of low polarisation fraction, allow us to compare multiple independent solutions for polarisation characteristics. The results show that the agreement between the two polarisation correction models is excellent. However, the values from Mopra with nominally circular polarisation are larger than would be acceptable. However, we also demonstrate that recording mixed polarisation modes and correcting post-correlation provide a high quality polarisation product. We report on the detailed tests of these strategies and assess that the array is ready for full polarisation operation.

KW - polarisation methods: data analysis

U2 - 10.1017/pasa.2019.3

DO - 10.1017/pasa.2019.3

M3 - Article

VL - 36

JO - Publications of the Astronomincal Society of Australia (PASA)

JF - Publications of the Astronomincal Society of Australia (PASA)

SN - 1323-3580

M1 - 013

ER -