Astronomy and Astrophysics – Astrophysics – Instrumentation and Methods for Astrophysics
Scientific paper
2010-03-10
Astronomy and Astrophysics
Astrophysics
Instrumentation and Methods for Astrophysics
PhD Thesis 2007, Universit\'e Paris Diderot [French]
Scientific paper
Atmospheric turbulence is an important limit to high angular resolution in astronomy. Interferometry resolved this issue by filtering the incoming light with single-mode fibers. Thanks to this technique, we obtained with the IOTA interferometer very precise measurements of the spatial frequencies of seven evolved stars. From these measurements, we performed a blind deconvolution to restore an image of the surface of the stars. Six of the them, Betelgeuse, Mu Cep, R leo, Mira, Chi Cyg and CH Cyg, feature very asymmetrical brightness distributions. On the other hand, the Arcturus data are extremely well fitted with a simple limb-darkened photospheric disc. From the observations of $\chi$ Cyg, we show that the star is surrounded by a molecular shell undergoing a ballistic motion. We propose to use the same technique of spatial filtering with single-mode fibers to correct for the effect of turbulence in the pupil of a telescope. Because the pupil is redundant, this technique does require a remapping of the pupil. We developed a dedicated algorithm to show that it was possible to reconstruct images at the diffraction limit of the telescope free of any speckle noise. Our simulations show that a high dynamic range (over 10^6) could be obtained in the visible on an 8 meter telescope. A lab experiment is under construction to validate the concept of this new instrument.
No associations
LandOfFree
Imagerie des étoiles évoluées par interférométrie. Réarrangement de pupille does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Imagerie des étoiles évoluées par interférométrie. Réarrangement de pupille, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Imagerie des étoiles évoluées par interférométrie. Réarrangement de pupille will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-342550