Table 2
Properties of the ice retrieved in the models compared to the ISM.
| Ice species | Eb (K) | Disk X/H (ppm) | ISM X/H (ppm) | Disk X/H2O (%) | ISM X/H2O (%) | Comet X/H2O (%) | 67P X/H2O (%) |
|---|---|---|---|---|---|---|---|
| H2O | 5705 | 30 | 80 | 100 | 100 | 100 | 100 |
| CO2:CO3:1 | 3196 | 6 | |||||
| − CO2 fraction | 4.5 | 22 | 15 | 13 | 2.0-30 | 4.7 | |
| − CO fraction | 1.5 | 28 | 5 | 28 | 0.4-30 | 3.1 | |
| CH4 | 1232 | 3.6 | 3.6 | <12 | 1.9 | 0.4-1.6 | 0.34 |
| NH3 | 5362 | 0.5 | 4.8 | 1.7 | 5.0 | 0.2-1.4 | 0.67 |
| CH3OH | 6621 | <0.5 | 4.8 | <1.7 | 3.8 | 0.2-7.0 | 0.21 |
Notes. Only CO2 and CO are considered to be mixed in this work. The ISM ice abundances relative to hydrogen are taken from the inheritance model in Ballering et al. (2021), the ISM ice abundances relative to water are taken from the background stars published in McClure et al. (2023), and cometary ice abundances relative to water are taken from Rubin et al. (2019).
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.