The NEID spectrograph is a R ∼ 120,000 resolution fiber-fed and highly stabilized spectrograph for extreme radial velocity (RV) precision. It is being commissioned at the 3.5 m WIYN telescope in Kitt Peak National Observatory with a desired instrumental precision of better than 30 cm s-1. NEID's bandpass of 380 - 930 nm enables the simultaneous wavelength coverage of activity indicators from the Ca HK lines in the blue to the Ca IR triplet in the IR. In this paper we will present our efforts to characterize and mitigate optical ghosts in the NEID spectrograph during assembly, integration and testing, and highlight several of the dominant optical element contributors such as the cross dispersion prism and input optics. We shall present simulations of the 2-D spectrum and discuss the predicted ghost features on the focal plane, and how they may impact the RV performance for NEID. We also present the mitigation strategy adopted for each ghost which may be applied to future instrument designs. This work will enable other instrument builders to potentially avoid some of these issues, as well as outline mitigation strategies.
|Original language||English (US)|
|Title of host publication||Ground-Based and Airborne Instrumentation for Astronomy VIII|
|Editors||Christopher J. Evans, Julia J. Bryant, Kentaro Motohara|
|State||Published - 2020|
|Event||Ground-Based and Airborne Instrumentation for Astronomy VIII 2020 - Virtual, Online, United States|
Duration: Dec 14 2020 → Dec 22 2020
|Name||Proceedings of SPIE - The International Society for Optical Engineering|
|Conference||Ground-Based and Airborne Instrumentation for Astronomy VIII 2020|
|Period||12/14/20 → 12/22/20|
Bibliographical noteFunding Information:
NEID is funded by JPL under contract 1547612. This work was partially supported by funding from the Center for Exoplanets and Habitable Worlds. The Center for Exoplanets and Habit-able Worlds is supported by the Pennsylvania State University, the Eberly College of Science,and the Pennsylvania Space Grant Consortium. We acknowledge support from NSF grants AST-1006676, AST-1126413, AST-1310885, the NASA Astrobiology Institute(NAI; NNA09DA76A), and the Penn State Astrobiology Research Center.
© 2020 SPIE
- Ghost analysis
- Optical design
- Scattered light