Protoplanets with core masses below the critical mass fill in their Roche lobe
We study the evolution of a protoplanet of a few earth masses embedded in a protoplanetary disc. If we assume that the atmosphere of the protoplanet, i.e. the volume of gas in hydrostatic equilibrium bound to the core, has a surface radius smaller than the Roche lobe radius, we show that it expands...
| Main Authors: | , |
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| Format: | Journal article |
| Language: | English |
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2011
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| _version_ | 1826274605002653696 |
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| author | Terquem, C Heinemann, T |
| author_facet | Terquem, C Heinemann, T |
| author_sort | Terquem, C |
| collection | OXFORD |
| description | We study the evolution of a protoplanet of a few earth masses embedded in a protoplanetary disc. If we assume that the atmosphere of the protoplanet, i.e. the volume of gas in hydrostatic equilibrium bound to the core, has a surface radius smaller than the Roche lobe radius, we show that it expands as it accretes both planetesimals and gas at a fixed rate from the nebula until it fills in the Roche lobe. The evolution occurs on a timescale shorter than the formation or migration timescales. Therefore, we conclude that protoplanets of a few earth masses have an atmosphere that extends to the Roche lobe surface, where it matches to the nebula. This is true even when the Bondi radius is smaller than the Roche lobe radius. This is in contrast to the commonly used models in which the static atmosphere extends up to the Bondi radius and is surrounded by a cold accretion flow. As a result, any calculation of the tidal torque exerted by the disc onto the protoplanet should exclude the material present in the Roche lobe, since it is bound to the protoplanet. |
| first_indexed | 2024-03-06T22:45:59Z |
| format | Journal article |
| id | oxford-uuid:5d30ebcb-16b6-498d-928c-a470525de535 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T22:45:59Z |
| publishDate | 2011 |
| record_format | dspace |
| spelling | oxford-uuid:5d30ebcb-16b6-498d-928c-a470525de5352022-03-26T17:32:53ZProtoplanets with core masses below the critical mass fill in their Roche lobeJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5d30ebcb-16b6-498d-928c-a470525de535EnglishSymplectic Elements at Oxford2011Terquem, CHeinemann, TWe study the evolution of a protoplanet of a few earth masses embedded in a protoplanetary disc. If we assume that the atmosphere of the protoplanet, i.e. the volume of gas in hydrostatic equilibrium bound to the core, has a surface radius smaller than the Roche lobe radius, we show that it expands as it accretes both planetesimals and gas at a fixed rate from the nebula until it fills in the Roche lobe. The evolution occurs on a timescale shorter than the formation or migration timescales. Therefore, we conclude that protoplanets of a few earth masses have an atmosphere that extends to the Roche lobe surface, where it matches to the nebula. This is true even when the Bondi radius is smaller than the Roche lobe radius. This is in contrast to the commonly used models in which the static atmosphere extends up to the Bondi radius and is surrounded by a cold accretion flow. As a result, any calculation of the tidal torque exerted by the disc onto the protoplanet should exclude the material present in the Roche lobe, since it is bound to the protoplanet. |
| spellingShingle | Terquem, C Heinemann, T Protoplanets with core masses below the critical mass fill in their Roche lobe |
| title | Protoplanets with core masses below the critical mass fill in their
Roche lobe |
| title_full | Protoplanets with core masses below the critical mass fill in their
Roche lobe |
| title_fullStr | Protoplanets with core masses below the critical mass fill in their
Roche lobe |
| title_full_unstemmed | Protoplanets with core masses below the critical mass fill in their
Roche lobe |
| title_short | Protoplanets with core masses below the critical mass fill in their
Roche lobe |
| title_sort | protoplanets with core masses below the critical mass fill in their roche lobe |
| work_keys_str_mv | AT terquemc protoplanetswithcoremassesbelowthecriticalmassfillintheirrochelobe AT heinemannt protoplanetswithcoremassesbelowthecriticalmassfillintheirrochelobe |