Applying a temporal systematics model to vector Apodizing Phase Plate coronagraphic data: TRAP4vAPP

Astronomy and Astrophysics, vol. 674, pp. A115

Abstract

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.

Authors 13

1. Pengyu Liu corresponding Aachen Leiden Observatory

   Leiden University · Royal Observatory · Leiden Observatory · University of Edinburgh

   Affiliation as printed

   Centre for Exoplanet Science, University of Edinburgh, Edinburgh, UK

   Leiden Observatory, Leiden University, PO Box 9531, 2300 RA Leiden, The Netherlands

   SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, UK

2. Alexander J. Bohn Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory , Leiden University , PO Box 9531 , 2300 RA Leiden , The Netherlands

   Leiden Observatory, Leiden University, PO Box 9531, 2300 RA Leiden, The Netherlands

3. David S. Doelman Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory , Leiden University , PO Box 9531 , 2300 RA Leiden , The Netherlands

   Leiden Observatory, Leiden University, PO Box 9531, 2300 RA Leiden, The Netherlands

4. Ben J. Sutlieff Aachen Leiden Observatory

   Leiden University · Royal Observatory · Leiden Observatory · University of Amsterdam · University of Edinburgh

   Affiliation as printed

   Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands

   Centre for Exoplanet Science, University of Edinburgh, Edinburgh, UK

   Leiden Observatory, Leiden University, PO Box 9531, 2300 RA Leiden, The Netherlands

   SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, UK

5. M. Samland

   Max Planck Institute for Astronomy

   Affiliation as printed

   Max-Planck-Institut für Astronomie , Königstuhl 17 , 69117 Heidelberg , Germany

   Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany

6. Matthew A. Kenworthy Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory , Leiden University , PO Box 9531 , 2300 RA Leiden , The Netherlands

   Leiden Observatory, Leiden University, PO Box 9531, 2300 RA Leiden, The Netherlands

7. Frans Snik Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory , Leiden University , PO Box 9531 , 2300 RA Leiden , The Netherlands

   Leiden Observatory, Leiden University, PO Box 9531, 2300 RA Leiden, The Netherlands

8. Jayne Birkby

   University of Oxford

   Affiliation as printed

   Astrophysics , University of Oxford , Denys Wilkinson Building , Keble Road , Oxford OX1 3RH , UK

   Astrophysics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK

9. Beth A. Biller

   Royal Observatory · University of Edinburgh

   Affiliation as printed

   Centre for Exoplanet Science , University of Edinburgh , Edinburgh , UK

   SUPA , Institute for Astronomy , University of Edinburgh , Royal Observatory , Blackford Hill , Edinburgh , EH9 3HJ , UK

   Centre for Exoplanet Science, University of Edinburgh, Edinburgh, UK

   SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh, EH9 3HJ, UK

10. Jared R. Males

    University of Arizona

    Affiliation as printed

    Steward Observatory , University of Arizona , 933 N. Cherry Ave. , Tucson , AZ 85721 , USA

    Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721, USA

11. Katie M. Morzinski

    University of Arizona

    Affiliation as printed

    Steward Observatory , University of Arizona , 933 N. Cherry Ave. , Tucson , AZ 85721 , USA

    Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721, USA

12. Laird M. Close

    University of Arizona

    Affiliation as printed

    Steward Observatory , University of Arizona , 933 N. Cherry Ave. , Tucson , AZ 85721 , USA

    Steward Observatory, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721, USA

13. Gilles P. P. L. Otten Aachen Leiden Observatory

    Leiden University · Institute of Astronomy and Astrophysics, Academia Sinica · Leiden Observatory · Academia Sinica

    Affiliation as printed

    Academia Sinica , Institute of Astronomy and Astrophysics , 11F Astronomy-Mathematics Building , NTU/AS campus , No. 1 , Section 4 , Roosevelt Rd. , Taipei 10617 , Taiwan

    Leiden Observatory , Leiden University , PO Box 9531 , 2300 RA Leiden , The Netherlands

    Academia Sinica, Institute of Astronomy and Astrophysics, 11F Astronomy-Mathematics Building, NTU/AS campus, No. 1, Section 4, Roosevelt Rd., Taipei 10617, Taiwan

    Leiden Observatory, Leiden University, PO Box 9531, 2300 RA Leiden, The Netherlands