Description
A combination of large collecting aperture and a highly efficient high-resolution spectrograph is essential for demanding exoplanet science cases, particularly the search for atmospheric biomarkers. We present a design study for a high-resolution spectroscopic facility for the LFAST telescope, an array that combines light from 2640 individual 0.76m telescopes, providing collecting area comparable to an ELT. Every individual telescope couples light to an optical fiber, which is fed to the proposed spectrometers, enabling custom formatting of the slit. We quantify the complexity of large etendue spectrographs, investigate their design trade-offs and compare the performance of instruments across a range of scales: from single, very large spectrometers in the visible and the near-IR, capable of spectrally analyzing the combined fiber output of a large number of telescopes, to multiple smaller spectrometers coupled to sub-arrays of equivalent 10-m, 3-m and individual 0.76-m telescopes. We find that manufacturing constraints and detector real estate are the dominant drivers of design decisions, and that subdividing each spectrograph into additional spectral channels increases the etendue each unit can accommodate.
| I am the presenting author | Yes |
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