The Tunable Filter Imager (TFI) of the JWST
Authors
D. Lafrenière (1), R. Doyon (1), J. Hutchings (2), M. Beaulieu (1), R. Abraham (3), L. Ferrrarese (2), A. Fullerton (4), R. Jayawardhana (3), D. Johnstone (2), M. Meyer (5), J. Pipher (6), N. Rowlands (7), M. Sawicki (8)
Affiliations
(1) Université de Montréal; (2) Herzberg Institute of Astrophysics - National Research Council of Canada; (3) University of Toronto; (4) Space Telescope Science Institute; (5) ETH Hoenggerberg; (6) University of Rochester; (7) Com Dev Ltd; (8) St-Mary’s University
Abstract
The Tunable Filter Imager (TFI) is a science camera packaged within the Fine Guidance Sensor module of the JWST, which is provided by the Canadian Space Agency. TFI uses of a low-order Fabry-Perot etalon to perform narrow-band imaging at any wavelength in the 1.6-2.6 µm and 3.2-4.9 µm ranges; the spectral resolving power varies between 80 and 140. TFI is equipped with a classical Lyot coronagraph that provides a contrast improvement of approximately 2.5 mag for angular separations above 0.3”. TFI is also equipped with a non-redundant aperture mask (NRM) in its pupil wheel; at a wavelength of 4.6 µm, the NRM provides an angular resolution of 75 mas and reaches a contrast of 10 mag. This regime of contrast and angular separation is unique to the TFI/NRM onboard JWST. The coronagraphic, spectral differential imaging and aperture masking interferometry capabilities of TFI provide the high contrast and high angular resolution that are essential for exoplanet detection; the tunable filter then allows spectral characterization at R 100. In this talk I will present a more detailed overview of the TFI and show some examples that illustrate its capabilities in the context of exoplanet search and characterization.