Correcting NIRISS charge migration reveals KELT-7 b as a metal-enriched (~92x solar) ultra-hot Jupiter with H2O, CO2 and TiO but no H- or clouds, orbiting a young metal-rich star.
J., Hutchings, J
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
The Near-Infrared Imager and Slitless Spectrograph (NIRISS) is the science module of the Canadian-built Fine Guidance Sensor (FGS) onboard the James Webb Space Telescope (JWST). NIRISS has four observing modes: 1) broadband imaging featuring seven of the eight NIRCam broadband filters, 2) wide-field slitless spectroscopy (WFSS) at a resolving power of $\sim$150 between 0.8 and 2.2 $\mu$m, 3) single-object cross-dispersed slitless spectroscopy (SOSS) enabling simultaneous wavelength coverage between 0.6 and 2.8 $\mu$m at R$\sim$700, a mode optimized for exoplanet spectroscopy of relatively bright ($J<6.3$) stars and 4) aperture masking interferometry (AMI) between 2.8 and 4.8 $\mu$m enabling high-contrast ($\sim10^{-3}-10^{-4}$) imaging at angular separations between 70 and 400 milliarcsec for relatively bright ($M<8$) sources. This paper presents an overview of the NIRISS instrument, its design, its scientific capabilities, and a summary of in-flight performance. NIRISS shows significantly better response shortward of $\sim2.5\,\mu$m resulting in 10-40% sensitivity improvement for broadband and low-resolution spectroscopy compared to pre-flight predictions. Two time-series observations performed during instrument commissioning in the SOSS mode yield very stable spectro-photometry performance within $\sim$10% of the expected noise. The first space-based companion detection of the tight binary star AB Dor AC through AMI was demonstrated.
representative citing papers
First mid-IR transmission spectrum of TOI-270 d shows molecular features with Bayesian evidence ln B = 2.8-5.3 and identifies candidate trace molecules from an agnostic search of 203 species.
ROSSINI achieves integral field spectroscopy without IFUs via rotational slitless imaging combined with tomographic reconstruction, recovering input datacubes to percent-level accuracy in numerical simulations.
AMIGO is an end-to-end differentiable forward model of JWST AMI that corrects detector systematics to recover high-precision astrometry and detect close high-contrast companions.
citing papers explorer
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Mitigating Charge Migration in JWST NIRISS Reveals That KELT-7 b is a Metal-enriched Ultra-hot Jupiter Orbiting a Young Metal-rich Star
Correcting NIRISS charge migration reveals KELT-7 b as a metal-enriched (~92x solar) ultra-hot Jupiter with H2O, CO2 and TiO but no H- or clouds, orbiting a young metal-rich star.
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The Mid-Infrared Transmission Spectrum of the Temperate Sub-Neptune TOI-270 d
First mid-IR transmission spectrum of TOI-270 d shows molecular features with Bayesian evidence ln B = 2.8-5.3 and identifies candidate trace molecules from an agnostic search of 203 species.
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Integral field spectroscopy with no IFUs: combining wide-field rotational slitless spectroscopy with tomographic reconstruction
ROSSINI achieves integral field spectroscopy without IFUs via rotational slitless imaging combined with tomographic reconstruction, recovering input datacubes to percent-level accuracy in numerical simulations.
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AMIGO: a Data-Driven Calibration of the JWST Interferometer
AMIGO is an end-to-end differentiable forward model of JWST AMI that corrects detector systematics to recover high-precision astrometry and detect close high-contrast companions.