تقرير
Constraints on the gas-phase C/O ratio of DR Tau's outer disk from CS, SO, and C$_2$H observations
| العنوان: | Constraints on the gas-phase C/O ratio of DR Tau's outer disk from CS, SO, and C$_2$H observations |
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| المؤلفون: | Huang, Jane, Bergin, Edwin A., Gal, Romane Le, Andrews, Sean M., Bae, Jaehan, Keyte, Luke, Sturm, J. A. |
| سنة النشر: | 2024 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | Millimeter wavelength observations of Class II protoplanetary disks often display strong emission from hydrocarbons and high CS/SO values, providing evidence that the gas-phase C/O ratio commonly exceeds 1 in their outer regions. We present new NOEMA observations of CS $5-4$, SO $7_6-6_5$ and $5_6-4_5$, C$_2$H $N=3-2$, HCN $3-2$, HCO$^+$ $3-2$, and H$^{13}$CO$^+$ $3-2$ in the DR Tau protoplanetary disk at a resolution of $\sim0.4''$ (80 au). Estimates for the disk-averaged CS/SO ratio range from $\sim0.4-0.5$, the lowest value reported thus far for a T Tauri disk. At a projected separation of $\sim180$ au northeast of the star, the SO moment maps exhibit a clump that has no counterpart in the other lines, and the CS/SO value decreases to $<0.2$ at its location. Thermochemical models calculated with DALI indicate that DR Tau's low CS/SO ratio and faint C$_2$H emission can be explained by a gas-phase C/O ratio that is $<1$ at the disk radii traced by NOEMA. Comparisons of DR Tau's SO emission to maps of extended structures traced by $^{13}$CO suggest that late infall may contribute to driving down the gas-phase C/O ratio of its disk. Comment: Accepted by ApJ |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2407.01679 |
| رقم الأكسشن: | edsarx.2407.01679 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |