arXiv subjects

William T. S. Deich

Publications and source records attributed to William T. S. Deich.

3 recordsLinked to original sources

arXiv2026

Validating the SCALES DRP: A Performance Study of the Medium-Resolution IFS Mode

We present a performance verification of the medium-resolution integral field spectrograph (IFS) mode of the SCALES Data Reduction Pipeline (SCALES-DRP) using data obtained during recent cryogenic cooldown testing. SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy), scheduled for deployment on the Keck II Telescope in late 2026, will be the first facility-class high-contrast thermal-infrared IFS, operating over the 2-5 micrometer wavelength range. The SCALES-DRP, developed within the Keck Data Reduction Pipeline Framework and implemented in Python, converts raw detector reads into calibrated three-dimensional datacubes using rectification matrices derived from position-dependent monochromatic lenslet point-spread functions, and supports both optimal and chi-sqaure-based spectral extraction to maximize signal-to-noise and extraction fidelity. We present laboratory verification results for the medium-resolution IFS mode, which combines a 0.34x0.36 arcsec lenslet subarray with an image slicer to achieve spectral resolutions of R ~ 2,000 - 5,000, focusing on the performance of the rectification matrices and the robustness of the extraction algorithms. These results demonstrate the readiness of the SCALES-DRP for instrument commissioning and early science operations. The pipeline is publicly available on GitHub.

astro-ph.IM↗

arXiv2025

SCALES-DRP : A Data Reduction Pipeline for an Upcoming Keck Thermal Infrared Spectrograph

We present the end-to-end data reduction pipeline for SCALES (Slicer Combined with Array of Lenslets for Exoplanet Spectroscopy), the upcoming thermal-infrared, diffraction-limited imager, and low and medium-resolution integral field spectrograph (IFS) for the Keck II telescope. The pipeline constructs a ramp from a set of reads and performs optimal extraction and chi-square extraction to reconstruct the 3D IFS datacube. To perform spectral extraction, wavelength calibration, and sky subtraction, the pipeline utilizes rectification matrices produced using position-dependent lenslet point spread functions (PSFs) derived from calibration exposures. The extracted 3D data cubes provide intensity values along with their corresponding uncertainties for each spatial and spectral measurement. The SCALES pipeline is under active development, implemented in Python within the Keck data reduction framework, and is openly available on GitHub along with dedicated documentation.

astro-ph.IM↗

arXiv2020

The Planet as Exoplanet Analog Spectrograph (PEAS): Design and First-Light

Exoplanets are abundant in our galaxy and yet characterizing them remains a technical challenge. Solar System planets provide an opportunity to test the practical limitations of exoplanet observations with high signal-to-noise data that we cannot access for exoplanets. However, data on Solar System planets differ from exoplanets in that Solar System planets are spatially resolved while exoplanets are unresolved point-sources. We present a novel instrument designed to observe Solar System planets as though they are exoplanets, the Planet as Exoplanet Analog Spectrograph (PEAS). PEAS consists of a dedicated 0.5-m telescope and off-the-shelf optics, located at Lick Observatory. PEAS uses an integrating sphere to disk-integrate light from the Solar System planets, producing spatially mixed light more similar to the spectra we can obtain from exoplanets. This paper describes the general system design and early results of the PEAS instrument.

astro-ph.IM↗