Probing dusty circumstellar environments with polarimetric aperture-masking interferometry

Autor(en)

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

Abstrakt

Aperture-masking interferometry allows diffraction-limited images to be

recovered despite the turbulent atmo­ sphere. 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 (rv1Omas)

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.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

The University of Sydney, Université de recherche Paris Sciences et Lettres, University of Manchester, Subaru Telescope

Band

8445

Anzahl der Seiten

13

DOI

https://doi.org/10.1117/12.925838

Publikationsdatum

07-2012

ÖFOS 2012

103004 Astrophysik, 103003 Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/203619dd-44b2-4221-8144-396495e9e875