Exoplanets Sciences With Nulling Interferometers And A Single-Mode Fiber-Fed Spectrograph

Illustration of a dual-aperture FN simulation. (a): Intensity of a point source that is located at an infinite distance, i.e., an unresolved star. (b): Transmission of a dual-aperture pupil plane. (c): The “footprint” of an on-axis single-mode fiber core after a beam-shaping device. (d): Intensity of the interferogram of the dual-aperture with a π phase offset. (e): Phase of the EM field of the interferogram as shown in (d). (f): Map of coupling efficiency

Understanding the atmospheres of exoplanets is a milestone to decipher their formation history and potential habitability. High-contrast imaging and spectroscopy of exoplanets is the major pathway towards the goal. Directly imaging of an exoplanet requires high spatial resolution.

Interferometry has proven to be an effective way of improving spatial resolution. However, means of combining interferometry, high-contrast imaging, and high-resolution spectroscopy have been rarely explored. To fill in the gap, we present the dual-aperture fiber nuller (FN) for current-generation 8-10 meter telescopes, which provides the necessary spatial and spectral resolution to (1) conduct follow-up spectroscopy of known exoplanets; and (2) detect planets in debris-disk systems.

The concept of feeding a FN to a high-resolution spectrograph can also be used for future space and ground-based missions. We present a case study of using the dual-aperture FN to search for biosignatures in rocky planets around M stars for a future space interferometry mission. Moreover, we discuss how a FN can be equipped on future extremely large telescopes by using the Giant Magellan Telescope (GMT) as an example.

Ji Wang (OSU), Colby Jurgenson (OSU)
Comments: Submitted to AAS Journals
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2007.15529 [astro-ph.IM] (or arXiv:2007.15529v1 [astro-ph.IM] for this version)
Submission history
From: Ji Wang
[v1] Thu, 30 Jul 2020 15:29:10 UTC (4,331 KB)

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