¹Sota Arakawa, ^2,3Takayuki Ushikubo, ⁴Ryosuke T. Tominaga
The Astrophysical Journal, 1008, 161
Open Access Link to Article [DOI: 10.3847/1538-4357/ae93a1]
¹Center for Mathematical Science and Advanced Technology, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, 236-0001, Japan
²Kochi Institute for Core Sample Research, EMS, Japan Agency for Marine-Earth Science and Technology, 200 Monobe-otsu, Nankoku, Kochi, 783-8502, Japan
³Marine Core Research Institute, Kochi University, 200 Monobe-otsu, Nankoku, Kochi, 783-8502, Japan
⁴Department of Earth and Planetary Sciences, Institute of Science Tokyo, 2-12-1 Ookayama, Meguro, Tokyo, 152-8550, Japan

Chondrules are thought to have formed during transient flash-heating events in dust-enriched regions of the solar protoplanetary disk. Although laboratory studies have characterized the oxygen isotopic compositions of chondritic materials, quantitative interpretations based on simulations of disk formation and evolution remain limited. Here, we perform one-dimensional simulations of disk formation and evolution by solving a diffusion–advection equation with mass infall from the parental cloud core. We compute the temporal evolution of oxygen isotopic compositions using an experimentally derived isotope-exchange model. We examine how the oxygen isotopic signatures of the disk depend on the radial distribution of infalling material and the composition of the parental cloud core. We find that the oxygen isotopic compositions of carbonaceous-chondrite chondrules can be reproduced if either (i) the radial extent of mass infall onto the disk is moderate (∼10 au), or (ii) it is large (>10 au) and the parental cloud core was ice-depleted and/or experienced weaker CO self-shielding than is commonly assumed. In contrast, if ordinary-chondrite chondrules formed inside the snow line under background temperatures of ≲500 K, their oxygen isotopic compositions may be difficult to explain within the present disk-evolution model, because oxygen isotopic exchange between silicates and vapor species proceeds efficiently only in the inner disk at T ≳ 500–600 K.