Exoplanet direct imaging in ground-based conditions on THD2 bench

التفاصيل البيبلوغرافية
العنوان: Exoplanet direct imaging in ground-based conditions on THD2 bench
المؤلفون: Potier, A., Baudoz, P., Galicher, R., Huby, E., Singh, G.
سنة النشر: 2019
المجموعة: Astrophysics
مصطلحات موضوعية: Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Earth and Planetary Astrophysics
الوصف: The next generation of ground-based instruments aims to break through the knowledge we have on exoplanets by imaging circumstellar environments always closer to the stars. However, direct imaging requires an AO system and high-contrast techniques like a coronagraph to reject the diffracted light of an observed star and an additional wavefront sensor to control quasi-static aberrations, including the non common path aberrations. To observe faint objects, a focal plane wavefront sensor with a sub-nanometric wavefront control capability is required. In the past few years, we developed the THD2 bench which is a testbed for high-contrast imaging techniques, working in visible and near infrared wavelengths and currently reaching contrast levels lower than 1e-8 under space-like simulated conditions. We recently added a turbulence wheel on the optical path which simulates the residuals given by a typical extreme adaptive optics system and we tested several ways to remove quasi-statics speckles. One way to estimate the aberrations is a method called pair-wise probing where we record few images with known-shapes we apply on the adaptive optics deformable mirror. Once estimated, we seek to minimize the focal-plane electric field by an algorithm called Electric Field Conjugation. In this paper, we present the first results obtained on the THD2 bench using these two techniques together in turbulent conditions. We then compare the achieved performance with the one expected when all the quasi-static speckles are corrected.
Comment: 9 pages, 3 figures, AO4ELT6 Qu\'ebec city
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/1910.09064
رقم الأكسشن: edsarx.1910.09064
قاعدة البيانات: arXiv