Detection of Dimethyl Ether in the Central Region of the MWC 480 Protoplanetary Disk
Year: 2024
Type: article
Abstract: Characterizing the chemistry of complex organic molecules (COMs) at the epoch of planet formation provides insights into the chemical evolution of the interstellar medium (ISM) and the origin of organic materials in our solar system. We report a detection of dimethyl ether (CH3OCH3) in the disk around the Herbig Ae star MWC 480 with sensitive Atacama Large Millimeter/submillimeter Array observations. This is the first detection of CH3OCH3 in a nontransitional Class II disk. The spatially unresolved, compact (≲25 au in radius) nature, broad line width (∼30 km s−1), and high excitation temperature (∼200 K) indicate the sublimation of COMs in the warm inner disk. Despite the detection of CH3OCH3, methanol (CH3OH), the most abundant COM in the ISM, has not been detected, from which we constrain the column density ratio of CH3OCH3/CH3OH ≳ 7. This high ratio may indicate the reprocessing of COMs during the disk phase, as well as the effect of the physical structure in the inner disk. We also find that this ratio is higher than in COM-rich transition disks recently discovered. This may indicate that in the full disk of MWC 480, COMs have experienced substantial chemical reprocessing in the innermost region, while the COM emission in the transition disks predominantly traces the inherited ice sublimating at the dust cavity edge located at larger radii (≳20 au).
Source: The Astrophysical Journal
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funders: National Science Foundation, National Aeronautics and Space Administration, Space Telescope Science Institute, National Radio Astronomy Observatory, Ministry of Education, Culture, Sports, Science and Technology, Korea Astronomy and Space Science Institute, National Astronomical Observatory of Japan, Agencia Nacional de Investigación y Desarrollo, National Science and Technology Council, Japan Society for the Promotion of Science, National Institutes of Natural Sciences, Fondo Nacional de Desarrollo Científico y Tecnológico
Awards: ASTROCHEMISTRY DURING STAR AND PLANET FORMATION, 惑星系形成円盤における元素組成の分布と進化：系外惑星大気の起源に迫る, Study of Planet Formation in Protostellar Disks with the ALMA Large Program, Search for snow-lines with high-resolution spectroscopic observations in the mid-infrared, G2428672771, Exploration of planetary system formation processes through the studies of chemical structures in protostellar objects, protoplanetary disks, and exoplanetary atmospheres, G2706722481, G3075338354, G4001094388, Exploration of universal planet formation processes through the theoretical and observational studies of chemical structures in protoplanetary disks and exoplanetary atmospheres, G433322167, G4456922908, G58316358, G5834573078, G6143742401, G6273510985, ALMA高解像度観測による若い惑星形成円盤の物理・化学構造の解明, G8044338558, G864584368, CENTRO DE ASTROFISICA Y TECNOLOGIAS AFINES (CATA)
OpenAlex ID: W4403198191