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Arxiv: Water Ice in the Edge-On Orion Silhouette Disk 114--426 from JWST NIRCam Images Published: 12/5/2024 7:15:28 PM Updated: 1/21/2025 6:10:08 PM

Paper abstract: We examine images of the protoplanetary disk 114--426 with JWST/NIRCam in 12bands. This large disk is oriented edge-on with a dark midplane flanked bylobes of scattered light. The outer edges of the midplane are seen insilhouette against the Orion Nebula, providing a unique opportunity to studyplanet-forming material in absorption. We discover a dip in the scattered lightof the disk at 3\,\micron -- compelling evidence for the presence of waterice. The 3\,\micron dip is also seen in the silhouette of the disk, where wequantify the ice abundance with models of pure absorption and avoid thecomplications of disk scattering effects. We find grain ice-to-refractory massratios of up to ~0.2, maximum grain sizes of 0.25 to 5\,\micron, and atotal dust plus ice mass of 0.46\,M_\oplus in the silhouette region. We alsodiscover excess absorption in the NIRCam bands that include the Paschen\alpha line, suggesting there may be excited atomic hydrogen in the disk.Examining the morphology of the scattered light lobes reveals that they arelaterally offset from each other and exhibit a brightness asymmetry that flipswith wavelength -- both evidence for a tilted inner disk in this system.