The first paper features the results of a study led by graduate student Romain Laugier who’s successfully adapted an angular differential observing technique commonly used in high-contrast imaging to the kernel-phase scenario. This approach, coined angular differential kernel-phase (ADK) takes advantage of the sky rotation experienced by the SCExAO instrument at the Nasmyth focus of the Subaru Telescope when the field rotator is turned off. The technique makes it possible to better calibrate the biasing effect introduced by AO-residuals in the presence of quasi-static aberrations. Whereas interferometric observations typically require to alternate between a target of interest and a calibration star, this new approach spends 100% of the observing time on the target of interest, making it a more efficient alternative.
The second paper features the result of a study led by KERNEL project PI Frantz Martinache. This paper goes back to the roots of kernel-phase. After several years of development of the XARA pipeline carried out in the context of the KERNEL project, it was time to revisit previous analysis results in the light of its latest developments. The paper shows that while overall successful, early uses of kernel-phase were not particularly careful. The paper shows that refined descriptions of the diffractive apertures by instruments leads to a major improvement of the kernel-phase analysis and reduces the importance of systematic errors.
Using these new aperture modeling prescriptions, the authors then reprocess previously published observations from ground-based and space-borne observatories and shows major improvements in both cases!
In the same vein as the ADK idea at the core of the Laugier et al (2020) publication, the paper quickly explores the possibility offered by consecutive observations at multiple wavelengths. For a target whose aspect would change depending on the wavelength, spectral differential kernel-phase (SDK?) would be a powerful observing mode that would spend
The KERNEL project, hosted by Observatoire de la Cote d’Azur (OCA) invites applications for a PhD project in the field of high-angular resolution astronomy. This position is funded by the European Research Council (ERC – CoG – grand agreement #683029) under the European Union’s Horizon 2020 research and innovation program. The add was also posted on EURAXESS.
The adaptive optics revolution
Adaptive Optics (AO) has changed the face of observational astronomy, making ground based telescope able to live up to their angular resolution potential, and allowing us to dream up the upcoming generation of large 30m-class giant segmented mirror telescopes (GSMTs). Yet despite its incredible achievements, AO still hasn’t fully succeded in bringing the quality of astronomical images to its full potential, required for modern observing techniques such as high-contrast imaging and/or coupling into single mode fibers, enabling the use of photonic technology.
Objectives of the PhD project
The next major breakthrough will come from using information of great
value, available in the focal plane, to directly to drive AO systems.
Such an approach is finally possible today, thanks to the availability
of high-cadence, low readout noise near-infrared detectors and that of
enhanced real time computing capabilities. Observatoire de la Côte
d’Azur (OCA) and the Subaru Telescope are teaming up to offer a PhD
project that will turn this ambitious goal into a reality. This PhD is
funded by the KERNEL project. It will be co-supervised by the KERNEL
project PI F. Martinache (OCA) and the Subaru Coronagraphic Extreme AO
(SCExAO) project lead O. Guyon (Subaru Telescope).
The successful applicant will benefit from state of the art hardware and expertise along with access to two complementary experimental setups, both taking advantage of the same software environment:
the KERNEL test-bench, located in Nice (France), with a unique multi-wavelength capability, and a segmented deformable provides the means to prototype applications for GSMTs and long baseline interferometry developments.
the SCExAO instrument itself, installed at the Nasmyth focus of the Subaru Telescope, located atop Mauna Kea (Hawaii USA), provides the means to validate strategies using unique on-sky validation capability and have a rapid impact on the community.
The PhD should preferably start in the Fall 2018. To apply, the candidate is required to send (email firstname.lastname@example.org) a copy of his vita, and a letter detailing his/her interest in the project along with a transcript of his/her master degree in physics, astronomy or a relevant engineering specialty. The candidate should be willing to work as part of a team, to collaborate with an international network of people involved with a wide variety of activities: data processing, astrophysical modeling, observing at the telescope, experimentation in optics and real-time computing.
Astronomy and Instrumentation by Frantz Martinache