Issue |
A&A
Volume 674, June 2023
|
|
---|---|---|
Article Number | A115 | |
Number of page(s) | 15 | |
Section | Planets and planetary systems | |
DOI | https://doi.org/10.1051/0004-6361/202245333 | |
Published online | 12 June 2023 |
Applying a temporal systematics model to vector Apodizing Phase Plate coronagraphic data: TRAP4vAPP
1
Leiden Observatory, Leiden University,
PO Box 9531,
2300
RA Leiden,
The Netherlands
2
SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory,
Blackford Hill,
Edinburgh,
EH9 3HJ,
UK
e-mail: pengyu.liu@ed.ac.uk
3
Centre for Exoplanet Science, University of Edinburgh,
Edinburgh,
UK
4
Anton Pannekoek Institute for Astronomy, University of Amsterdam,
Science Park 904,
1098
XH Amsterdam,
The Netherlands
5
Max-Planck-Institut für Astronomie,
Königstuhl 17,
69117
Heidelberg,
Germany
6
Astrophysics, University of Oxford, Denys Wilkinson Building,
Keble Road,
Oxford
OX1 3RH,
UK
7
Steward Observatory, University of Arizona,
933 N. Cherry Ave.,
Tucson,
AZ 85721,
USA
8
Academia Sinica, Institute of Astronomy and Astrophysics,
11F Astronomy-Mathematics Building, NTU/AS campus, No. 1, Section 4, Roosevelt Rd.,
Taipei
10617,
Taiwan
Received:
31
October
2022
Accepted:
24
April
2023
Context. The vector Apodizing Phase Plate (vAPP) is a pupil plane coronagraph that suppresses starlight by forming a dark hole in its point spread function (PSF). The unconventional and non-axisymmetrical PSF arising from the phase modification applied by this coronagraph presents a special challenge to post-processing techniques.
Aims. We aim to implement a recently developed post-processing algorithm, temporal reference analysis of planets (TRAP) on vAPP coronagraphic data. The property of TRAP that uses non-local training pixels, combined with the unconventional PSF of vAPP, allows for more flexibility than previous spatial algorithms in selecting reference pixels to model systematic noise.
Methods. Datasets from two types of vAPPs are analysed: a double grating-vAPP (dgvAPP360) that produces a single symmetric PSF and a grating-vAPP (gvAPP180) that produces two D-shaped PSFs. We explore how to choose reference pixels to build temporal systematic noise models in TRAP for them. We then compare the performance of TRAP with previously implemented algorithms that produced the best signal-to-noise ratio (S/N) in companion detections in these datasets.
Results. We find that the systematic noise between the two D-shaped PSFs is not as temporally associated as expected. Conversely, there is still a significant number of systematic noise sources that are shared by the dark hole and the bright side in the same PSF. We should choose reference pixels from the same PSF when reducing the dgvAPP360 dataset or the gvAPP180 dataset with TRAP. In these datasets, TRAP achieves results consistent with previous best detections, with an improved S/N for the gvAPP180 dataset.
Key words: planets and satellites: detection / methods: data analysis / instrumentation: high angular resolution / techniques: high angular resolution / techniques: image processing
© The Authors 2023
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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