The VLA Orion Nebula Cluster Disk Survey 86 views

We present new Karl G. Jansky Very Large Array observations at 7 and 10 mm that have mapped the Orion Nebula Cluster with the highest angular resolution (0.06") and deepest sensitivity (10 μJy) to date at these wavelengths. We mosaicked a field containing 279 disks that have been previously detected at shorter millimeter wavelengths with the Atacama Large Millimeter/submillimeter Array. We detect 113 disks at 7 and 10 mm. We measure the 7 and 10 mm flux of each disk and combine these flux measurements with previous high angular resolution (<0.1"), 0.87, 3.1, and 13 mm observations to construct millimeter spectral energy distributions for each disk. We identify fifteen disks with mm spectra composed entirely of dust emission that is optically thick at short millimeter wavelengths but optically thin at long millimeter wavelengths. The remaining disks have millimeter spectra composed of both dust emission and from sources of non-dust emission, such as free-free emission. For the fifteen disks whose millimeter SEDs are composed entirely of dust emission, we convert their 7 mm continuum fluxes into a disk mass, and find that these mass measurements are ~5-50 times greater than the values derived at submillimeter wavelengths under the assumption of optically thin dust. Our results suggest that many disks in the ONC may be significantly more massive than previously estimated, and that disks in similar clustered star-forming environments may retain enough mass for planet formation despite the harsh radiation environment.

BS (Bachelor of Science)

2026-05-08