JWST NIRCam data (projected)

JWST NIRCam images of Jupiter's northern H3+ auroral emission projected onto a latitude-longitude grid at an altitude of 500 km. These observations were obtained as part of JWST program 4566 on 25 December 2023, using the long wavelength channel of NIRCam with the CLEAR pupil aperture stop and F335M filter. The data are presented in units of radiance in μW m−2 sr−1, and have been reduced as described in Nichols et al. (2024). The radiance values have been line-of-sight corrected using a cosine dependence on observation angle. The data are stored in the first extension of each FITS file, in arrays of shape (n_integrations, nx), where n_integrations is the number of integrations stored in this file, and nx is the number of positions for each integration. For efficiency of storage, the data for each image have been flattened to a 1D array, and this can be inflated to a 2D latitude-longitude grid using the accompanying Python code in the file jwstimage.py (which also uses the pixel index information stored in the included file expaurarr_north_iinx_jinx.npz), as shown below. The observation almanac information is stored in the header. To read and plot the file, the code first needs to be adapted to point to relevant directories on your machine, then:

import jwstimage as j

im = jwst.JWSTProjImage('filename')

im.readJWSTFile()

im.image = im.limbBrighteningCorrection()

integration_number=0

im.tvPolar(integration_number, vmin=20, vmax=200, satovals='None')