The JWST Early Release Science Program for Direct Observations of Exoplanetary Systems. IV. NIRISS Aperture Masking Interferometry Performance and Lessons Learned
Authors: Sallum Steph , Ray Shrishmoy , Kammerer Jens , Sivaramakrishnan Anand , Cooper Rachel , Greebaum Alexandra Z. , Thatte Deepashri , De Furio Matthew , Factor Samuel M. , Meyer Michael R. , Stone Jordan M. , Carter Aarynn , Biller Beth , Hinkley Sasha , Skemer Andrew , Suárez Genaro , Leisenring Jarron M. , Perrin Marshall D. , Kraus Adam L. , Absil Olivier , Balmer William O. , Betti Sarah K. , Boccaletti Anthony , Bonavita Mariangela , Bonnefoy Mickael , Booth Mark , Bowler Brendan P. , Briesemeister Zackery W. , Bryan Marta L. , Calissendorff Per , Cantalloube Faustine , Chauvin Gael , Chen Christine H. , Choquet Elodie , Christiaens Valentin , Cugno Gabriele , Currie Thayne , Danielski Camilla , Dupuy Trent J. , Faherty Jacqueline K. , Fitzgerald Michael P. , Fortney Jonathan J. , Franson Kyle , Girard Julien H. , Grady Carol A. , Gonzales Eileen C. , Henning Thomas , Hines Dean C. , Hoch Kielan K. W. , Hood Callie E. , Howe Alex R. , Janson Markus , Kalas Paul , Kennedy Grant M. , Kenworthy Matthew A. , Kervella Pierre , Kitzmann Daniel , Kuzuhara Masayuki , Lagrange Anne-Marie , Lagage Pierre-Olivier , Lawson Kellen , Lazzoni Cecilia , Lew Ben W. P. , Liu Michael C. , Liu Pengyu , Llop-Sayson Jorge , Lloyd James P. , Lueber Anna , Macintosh Bruce , Manjavacas Elena , Marino Sebastian , Marley Mark S. , Marois Christian , Martinez Raquel A. , Matthews Brenda C. , Matthews Elisabeth C. , Mawet Dimitri , Mazoyer Johan , McElwain Michael W. , Metchev Stanimir , Miles Brittany E. , Millar-Blanchaer Maxwell A. , Molliere Paul , Moran Sarah E. , Morley Caroline V. , Mukherjee Sagnick , Palma-Bifani Paulina , Pantin Eric , Patapis Polychronis , Petrus Simon , Pueyo Laurent , Quanz Sascha P. , Quirrenbach Andreas , Rebollido Isabel , Redai Jea Adams , Ren Bin B. , Rickman Emily , Samland Matthias , Sargent B. A. , Schlieder Joshua E. , Schneider Glenn , Stapelfeldt Karl R. , Sutlieff Ben J. , Tamura Motohide , Tan Xianyu , Theissen Christopher A. , Uyama Taichi , Vigan Arthur , Vasist Malavika , Vos Johanna M. , Wagner Kevin , Wang Jason J. , Ward-Duong Kimberly , Whiteford Niall , Wolff Schuyler G. , Worthen Kadin , Wyatt Mark C. , Ygouf Marie , Zhang Xi , Zhang Keming , Zhang Zhoujian , Zhou Yifan , Zurlo Alice 
Published: February 2024

We present a performance analysis for the aperture masking interferometry (AMI) mode on board the James Webb Space Telescope Near Infrared Imager and Slitless Spectrograph (JWST/NIRISS). Thanks to self-calibrating observables, AMI accesses inner working angles down to and even within the classical diffraction limit. The scientific potential of this mode has recently been demonstrated by the Early Release Science (ERS) 1386 program with a deep search for close-in companions in the HIP 65426 exoplanetary system. As part of ERS 1386, we use the same data set to explore the random, static, and calibration errors of NIRISS AMI observables. We compare the observed noise properties and achievable contrast to theoretical predictions. We explore possible sources of calibration errors and show that differences in charge migration between the observations of HIP 65426 and point-spread function calibration stars can account for the achieved contrast curves. Lastly, we use self-calibration tests to demonstrate that with adequate calibration NIRISS F380M AMI can reach contrast levels of ∼9–10 mag at ≳λ/D. These tests lead us to observation planning recommendations and strongly motivate future studies aimed at producing sophisticated calibration strategies taking these systematic effects into account. This will unlock the unprecedented capabilities of JWST/NIRISS AMI, with sensitivity to significantly colder, lower-mass exoplanets than lower-contrast ground-based AMI setups, at orbital separations inaccessible to JWST coronagraphy.