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Proceedings Paper

Study on a multi-delay spectral interferometry for stellar radial velocity measurement
Author(s): Kai Zhang; Haijiao Jiang; Jin Tang; Hangxin Ji; Yongtian Zhu; Liang Wang
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Paper Abstract

High accuracy radial velocity measurement isn’t only one of the most important methods for detecting earth-like Exoplanets, but also one of the main developing fields of astronomical observation technologies in future. Externally dispersed interferometry (EDI) generates a kind of particular interference spectrum through combining a fixed-delay interferometer with a medium-resolution spectrograph. It effectively enhances radial velocity measuring accuracy by several times. Another further study on multi-delay interferometry was gradually developed after observation success with only a fixed-delay, and its relative instrumentation makes more impressive performance in near Infrared band. Multi-delay is capable of giving wider coverage from low to high frequency in Fourier field so that gives a higher accuracy in radial velocity measurement. To study on this new technology and verify its feasibility at Guo Shoujing telescope (LAMOST), an experimental instrumentation with single fixed-delay named MESSI has been built and tested at our lab. Another experimental study on multi-delay spectral interferometry given here is being done as well. Basically, this multi-delay experimental system is designed in according to the similar instrument named TEDI at Palomar observatory and the preliminary test result of MESSI. Due to existence of LAMOST spectrograph at lab, a multi-delay interferometer design actually dominates our work. It’s generally composed of three parts, respectively science optics, phase-stabilizing optics and delay-calibrating optics. To switch different fixed delays smoothly during observation, the delay-calibrating optics is possibly useful to get high repeatability during switching motion through polychromatic interferometry. Although this metrology is based on white light interferometry in theory, it’s different that integrates all of interference signals independently obtained by different monochromatic light in order to avoid dispersion error caused by broad band in big optical path difference (OPD).

Paper Details

Date Published: 28 July 2014
PDF: 8 pages
Proc. SPIE 9147, Ground-based and Airborne Instrumentation for Astronomy V, 914757 (28 July 2014); doi: 10.1117/12.2055562
Show Author Affiliations
Kai Zhang, Nanjing Institute of Astronomical Optics and Technology (China)
Haijiao Jiang, Nanjing Institute of Astronomical Optics and Technology (China)
Jin Tang, Nanjing Institute of Astronomical Optics and Technology (China)
Hangxin Ji, Nanjing Institute of Astronomical Optics and Technology (China)
Yongtian Zhu, Nanjing Institute of Astronomical Optics and Technology (China)
Liang Wang, National Astronomical Observatories (China)


Published in SPIE Proceedings Vol. 9147:
Ground-based and Airborne Instrumentation for Astronomy V
Suzanne K. Ramsay; Ian S. McLean; Hideki Takami, Editor(s)

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