Probing dusty circumstellar environments with polarimetric aperture-masking interferometry

Date

2012

Authors

Norris, Barnaby R M
Tuthill, Peter G
Lacour, Sylvestre
Zijlstra, Albert A
Lykou, Foteini
Evans, Thomas M
Stewart, Paul
Bedding, Timothy Russell
Guyon, Olivier
Martinache, Frantz

Journal Title

Journal ISSN

Volume Title

Publisher

SPIE - The International Society for Optical Engineering

Abstract

Aperture-masking interferometry allows diffraction-limited images to be recovered despite the turbulent atmosphere. Here, this approach has been combined with polarimetry to form a novel technique allowing the dusty environments of mass-losing stars (so-called AGB stars) and proto-planetary and debris disks to be imaged, the characterisation of which is key to understanding the recycling of matter and the formation of new planetary systems. Polarimetric aperture-masking interferometry produces images by exploiting the fact that starlight scattered by circumstellar dust becomes strongly polarised. Essentially, aperture-masking allows access to the small spatial scales (∼10mas) necessary while polarimetry allows light from the dust and star to be differentiated. Furthermore, measurements at multiple wavelengths allow dust grain sizes to be calculated using Mie scattering theory. Excellent results have already been obtained at near-IR wavelengths using the NACO instrument at the VLT. The next step is to leverage the higher spatial resolution and polarisation signal found in the visible, rather than near-IR. To this end, a new instrument allowing precision polarimetric aperture masking interferometry at 600-800nm is being developed for an 8m class telescope, details of which will also be presented.

Description

Keywords

Keywords: AGB stars; Aperture masking interferometry; Circumstellar; Circumstellar dust; Debris disk; Diffraction limited; Dust grains; Mie scattering theory; Multiple wavelengths; Near-IR; New instrument; Novel techniques; Optical interferometric polarimetries; Op AGB stars; Aperture masking; Optical interferometric polarimetry; Optical interferometry; Transition disks

Citation

Source

Proceedings of SPIE - The International Society for Optical Engineering

Type

Conference paper

Book Title

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Restricted until

2037-12-31