Authors

Szymon Gladysz Niranjan A. Thatte Graeme Salter Roberto Baena Galle Fraser Clarke Matthias Tecza Laurent Jolissaint

Affiliations

Szymon Gladysz - Israel Institute of Technology

Niranjan A. Thatte - University of Oxford

Graeme Salter - University of New South Wales

Roberto Baena Galle - University of Barcelona

Fraser Clarke - University of Oxford

Matthias Tecza - University of Oxford

Laurent Jolissaint - aquilAOptics

Abstract

HARMONI is a proposed visible and near-infrared integral field spectrograph for the European Extremely Large Telescope. We are exploring the potential of using HARMONI for high-contrast science, e.g. observations of exoplanets. Although HARMONI is not fed by extreme adaptive optics we show that substantial contrasts can be achieved by combining single-conjugate AO with coronagraphy and post-processing of the hyperspectral data cube using spectral deconvolution. HARMONI will be well suited for follow-up spectroscopy of planets detected by 8m class instruments, emphasizing their characterisation. We implement models of telescope aberrations: due to wind buffeting on M1, due to windshake on M2, due to rolled segment edges, as well as the ones resulting from M1 phasing and individual segment warping affected by thermal and gravity effects. Additionally, we investigate the impact of post-AO differential aberrations. We also look at possible improvements to spectral deconvolution which is our method of choice for data post-processing. Finally, we make predictions of achievable contrast which translates to the ability to characterise various types of exoplanets in detail.