Water Ice in the Edge-on Orion Silhouette Disk 114–426 from JWST NIRCam Images
We examine images of the protoplanetary disk 114–426 with JWST/NIRCam in 12 bands. This large disk is oriented edge on with a dark midplane flanked by lobes of scattered light.
The outer edges of the midplane are seen in silhouette against the Orion Nebula, providing a unique opportunity to study planet-forming material in absorption.
We discover a dip in the scattered light of the disk at 3 μm—compelling evidence for the presence of water ice. The 3 μm dip is also seen in the silhouette of the disk, where we quantify the ice abundance with models of pure absorption and avoid the complications of disk scattering effects.
We find grain ice-to-refractory mass ratios of up to ~0.2, maximum grain sizes of 0.25–5 μm, and a total dust plus ice mass of 0.46 M⊕ in the silhouette region. We also discover excess absorption in the NIRCam bands that include the Paα line, suggesting there may be excited atomic hydrogen in the disk.
Examining the morphology of the scattered light lobes reveals that they are laterally offset from each other and exhibit a brightness asymmetry that flips with wavelength—both evidence for a tilted inner disk in this system.
Images of 114–426 in the 12 NIRCam bands, ordered from shortest to longest wavelength. The SW channel images have been resampled onto the coarser pixel scale of the LW channel images. Each panel is 27 × 24 with north up and east left. The color bar shows the brightness in units of MJy sr−1. — The Astrophysical Journal
Water Ice in the Edge-on Orion Silhouette Disk 114–426 from JWST NIRCam Images, The Astrophysical Journal (open access)
Astrobiology, Astrochemistry,
