Implications of Evaporative Cooling by H2 for 1I/‘Oumuamua
| Autor: | Thiem Hoang, Abraham Loeb |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | The Astrophysical Journal Letters, Vol 951, Iss 2, p L34 (2023) |
| Druh dokumentu: | article |
| ISSN: | 2041-8213 2041-8205 |
| DOI: | 10.3847/2041-8213/acdf57 |
| Popis: | The first interstellar object observed in our solar system, 1I/‘Oumuamua, exhibited several peculiar properties, including extreme elongation and nongravitational acceleration. Bergner & Seligman (hereafter BS23) proposed that evaporation of trapped H _2 created by cosmic rays can explain the nongravitational acceleration. However, their modeling of the thermal structure of 1I/‘Oumuamua ignored the crucial cooling effect of evaporating H _2 . By taking into account the cooling by H _2 evaporation, we show that the surface temperature of H _2 -water ice is a factor of 9 lower than the case without evaporative cooling. As a result, the thermal speed of outgassing H _2 is decreased by a factor of 3. Our one-dimensional thermal modeling that takes into account evaporative cooling for two chosen values of thermal conductivity of κ = 0.01 and 0.1 WK ^−1 m ^−1 shows that the water ice volume available for H _2 sublimation at T > 30 K would be reduced by a factor of 9 and 5 compared to the results of BS23, not enabling enough hydrogen to propel 1I/‘Oumuamua. |
| Databáze: | Directory of Open Access Journals |
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