(DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms?
Abstract. We examine the distributions of eccentricity and host star metallicity of exoplanets as a function of their mass. Planets with M sin i�4 MJ have an eccentricity distribution consistent with that of binary stars, while planets with M sin i�4 MJ are less eccentric than binary stars and more...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.255.8902 2023-05-15T16:39:19+02:00 (DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms? Ignasi Ribas Jordi Miralda-escudé The Pennsylvania State University CiteSeerX Archives 2008 application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.255.8902 http://arxiv.org/pdf/astro-ph/0606009v1.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.255.8902 http://arxiv.org/pdf/astro-ph/0606009v1.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://arxiv.org/pdf/astro-ph/0606009v1.pdf – binaries general – Stars low-mass brown dwarfs – Stars text 2008 ftciteseerx 2016-01-07T19:56:14Z Abstract. We examine the distributions of eccentricity and host star metallicity of exoplanets as a function of their mass. Planets with M sin i�4 MJ have an eccentricity distribution consistent with that of binary stars, while planets with M sin i�4 MJ are less eccentric than binary stars and more massive planets. In addition, host star metallicities decrease with planet mass. The statistical significance of both of these trends is only marginal with the present sample of exoplanets. To account for these trends, we hypothesize that there are two populations of gaseous planets: the low-mass population forms by gas accretion onto a rock-ice core in a circumstellar disk and is more abundant at high metalliticities, and the high-mass population forms directly by fragmentation of a pre-stellar cloud. Planets of the first population form in initially circular orbits and grow their eccentricities later, and may have a mass upper limit from the total mass of the disk that can be accreted by the core. The second population may have a mass lower limit resulting from opacity-limited fragmentation. This would roughly divide the two populations in mass, although they would likely overlap over some mass range. If most objects in the second population form before the pre-stellar cloud becomes highly opaque, they would have to be initially located in orbits larger than ∼ 30 AU, and would need to migrate to the much smaller orbits in which they are observed. The higher mean orbital eccentricity of the second population might be caused by the larger required intervals of radial migration, and the brown dwarf desert might be due to the inability of Text ice core Unknown |
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– binaries general – Stars low-mass brown dwarfs – Stars |
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– binaries general – Stars low-mass brown dwarfs – Stars Ignasi Ribas Jordi Miralda-escudé (DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms? |
topic_facet |
– binaries general – Stars low-mass brown dwarfs – Stars |
description |
Abstract. We examine the distributions of eccentricity and host star metallicity of exoplanets as a function of their mass. Planets with M sin i�4 MJ have an eccentricity distribution consistent with that of binary stars, while planets with M sin i�4 MJ are less eccentric than binary stars and more massive planets. In addition, host star metallicities decrease with planet mass. The statistical significance of both of these trends is only marginal with the present sample of exoplanets. To account for these trends, we hypothesize that there are two populations of gaseous planets: the low-mass population forms by gas accretion onto a rock-ice core in a circumstellar disk and is more abundant at high metalliticities, and the high-mass population forms directly by fragmentation of a pre-stellar cloud. Planets of the first population form in initially circular orbits and grow their eccentricities later, and may have a mass upper limit from the total mass of the disk that can be accreted by the core. The second population may have a mass lower limit resulting from opacity-limited fragmentation. This would roughly divide the two populations in mass, although they would likely overlap over some mass range. If most objects in the second population form before the pre-stellar cloud becomes highly opaque, they would have to be initially located in orbits larger than ∼ 30 AU, and would need to migrate to the much smaller orbits in which they are observed. The higher mean orbital eccentricity of the second population might be caused by the larger required intervals of radial migration, and the brown dwarf desert might be due to the inability of |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Ignasi Ribas Jordi Miralda-escudé |
author_facet |
Ignasi Ribas Jordi Miralda-escudé |
author_sort |
Ignasi Ribas |
title |
(DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms? |
title_short |
(DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms? |
title_full |
(DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms? |
title_fullStr |
(DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms? |
title_full_unstemmed |
(DOI: will be inserted by hand later) The Eccentricity-Mass Distribution of Exoplanets: Signatures of Different Formation Mechanisms? |
title_sort |
(doi: will be inserted by hand later) the eccentricity-mass distribution of exoplanets: signatures of different formation mechanisms? |
publishDate |
2008 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.255.8902 http://arxiv.org/pdf/astro-ph/0606009v1.pdf |
genre |
ice core |
genre_facet |
ice core |
op_source |
http://arxiv.org/pdf/astro-ph/0606009v1.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.255.8902 http://arxiv.org/pdf/astro-ph/0606009v1.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766029655713775616 |