2021A&A...653A.138D


Query : 2021A&A...653A.138D

2021A&A...653A.138D - Astronomy and Astrophysics, volume 653A, 138-138 (2021/9-1)

RHAPSODIE: Reconstruction of High-contrAst Polarized SOurces and Deconvolution for cIrcumstellar Environments.

DENNEULIN L., LANGLOIS M., THIEBAUT E. and PUSTELNIK N.

Abstract (from CDS):


Context. Polarimetric imaging is one of the most effective techniques for the high-contrast imaging and characterization of circumstellar environments. These environments can be characterized through direct-imaging polarimetry at near-infrared wavelengths. The Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE)/IRDIS instrument, installed on the Very Large Telescope (VLT) in its dual-beam polarimetric imaging mode, offers the capability to acquire polarimetric images at high contrast and high angular resolution. However, dedicated image processing is needed to eliminate the contamination from the stellar light, instrumental polarization effects, and blurring from the instrumental point spread function.
Aims. We aim to reconstruct and deconvolve the near-infrared polarization signal from circumstellar environments.
Methods. We used observations of these environments obtained with the high-contrast imaging infrared polarimeter SPHERE-IRDIS at the VLT. We developed a new way to extract the polarimetric signal using an inverse approach method that benefits from the additional knowledge of the detected signal formation process. The method includes a weighted data fidelity term and smooth penalization, and it takes the instrumental polarization into account.
Results. This method enables us to accurately measure the polarized intensity and angle of linear polarization of circumstellar disks by taking into account the noise statistics and the convolution by the instrumental point spread function. It has the capacity to use incomplete polarimetry cycles, which enhance the sensitivity of the observations. The method improves the overall performances in particular for instances of both low signal-to-noise (S/N) and small polarized flux compared to standard methods.
Conclusions. By increasing the sensitivity and including deconvolution, our method will allow for more accurate studies of these disks morphology, especially in the innermost regions. It also will enable more accurate measurements of the angle of linear polarization at low S/N, which would lead to in-depth studies of dust properties. Finally, the method will enable more accurate measurements of the polarized intensity, which is critical for the construction of scattering phase functions.

Abstract Copyright: © L. Denneulin et al. 2021

Journal keyword(s): methods: numerical - techniques: polarimetric - methods: data analysis - techniques: high angular resolution - protoplanetary disks - techniques: image processing

Simbad objects: 18

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Number of rows : 18
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2023
#notes
1 V* HL Tau Or* 04 31 38.5107609312 +18 13 57.859747968   15.89 14.49 14.39   K5 1381 0
2 HD 36112 Ae* 05 30 27.5285630040 +25 19 57.076288752   8.57 8.27     A8Ve 448 0
3 HD 61005 PM* 07 35 47.4623556456 -32 12 14.045086368   8.96 8.22     G8Vk 215 0
4 V* TW Hya TT* 11 01 51.9053285064 -34 42 17.033218380   11.94 10.50 10.626 9.18 K6Ve 1825 1
5 V* T Cha Or* 11 57 13.5245085552 -79 21 31.530508884   10.00 11.86     K0e 269 1
6 HD 106906 * 12 17 53.1915103944 -55 58 31.893027240   8.95 8.89 8.46   F5V 142 0
7 HD 109573 PM* 12 36 01.0317461592 -39 52 10.220465388   5.786 5.774 7.25 5.81 A0V 610 1
8 CPD-68 1894 TT* 13 22 07.5421944624 -69 38 12.219391716   11.38 10.393   9.117 K1Ve 149 0
9 CD-40 8434 TT* 14 08 10.1545500744 -41 23 52.573291080   13.42 12.18 11.71 10.506 K7IVe 294 0
10 THA 15-12 Or* 15 56 09.2066646912 -37 56 06.126118692   13.12 11.93 11.45   M0e 388 0
11 HD 142527 Ae* 15 56 41.8882637904 -42 19 23.248281828   9.04 8.34     F6III 601 1
12 V* RU Lup TT* 15 56 42.3108692112 -37 49 15.473946900 9.27 10.07 9.60     K7/M0e 449 0
13 V* RY Lup Or* 15 59 28.3864710696 -40 21 51.249496176   12.62 9.90     G8/K1IV-V 216 0
14 V* MY Lup TT* 16 00 44.5202267160 -41 55 30.935126748   12.64 12.17 11.06   K0 104 0
15 WRAY 15-1443 TT* 16 15 20.2341630672 -32 55 05.097631872 13.88 13.22 12.00 11.21 10.50 K5 87 0
16 HD 163296 Ae* 17 56 21.2881851168 -21 57 21.871819008 7.00 6.93 6.85 6.86 6.67 A1Vep 1031 0
17 ASAS J181422-3246.2 Em* 18 14 22.0736727072 -32 46 10.132941432   14.14 12.78 12.316 10.380 M1Ve 45 0
18 HD 197481 BY* 20 45 09.5324974119 -31 20 27.237889841   10.05 8.627 9.078 6.593 M1VeBa1 1083 0

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2023.06.03-23:06:03

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