Deriving Spectral Maps from JWST Data : A Study of Enceladus’ Plumes

Sammanfattning: This study investigates the presence of water vapor plumes in the region south of Enceladus, a moon in the Saturnian system, through observations conducted by the James Webb Space Telescope. Enceladus is believed to harbor a subsurface ocean or localized water reservoir that gives rise to water geysers, expelling vapor into its tenuous atmosphere and outer space. On the 9th of November 2022, the James Webb Space Telescope made its first observations of the satellite using its Near-Infrared Spectrograph. The instrument's high sensitivity and spectral resolution offer the potential to measure these Enceladus' water vapor plumes, providing an opportunity to study this feature from a telescope located near Earth. However, it remains uncertain whether the obtained results are consistent with previous missions or if the instrument is even capable of conducting detailed examinations of the plumes. Hence, the primary objective of this research is to gain insights into the methodology of conducting scientific investigations of Enceladus and to understand the available data. More specifically, the aim is to verify the presence of the moon's water vapor plumes through a comprehensive analysis of the obtained data. The approach involves deriving spectral maps and extracting residual spectra that are used for comparisons with a reference spectrum entailing known water vapor emission features. The results reveal distinct emission peaks in the extracted spectra that closely resemble the features of water vapor. Additionally, the calculated column density of 6.25 - 8.25E+14 cm-2 over a region of 8.16E+07 km2 closely aligns with observations from the Herschel Space Observatory and Cassini mission. This outcome strongly supports the hypothesis that water vapor plumes are present in the area south of Enceladus, verifying the feasibility of using the James Webb Space Telescope for detecting and studying the characteristics of Enceladus' plumes.