Your browser doesn't support javascript.
loading
COMPOSITIONAL DIVERSITY IN THE ATMOSPHERES OF HOT NEPTUNES, WITH APPLICATION TO GJ 436b.
Moses, J I; Line, M R; Visscher, C; Richardson, M R; Nettelmann, N; Fortney, J J; Barman, T S; Stevenson, K B; Madhusudhan, N.
Afiliación
  • Moses JI; Space Science Institute, 4750 Walnut Street, Suite 205, Boulder, CO, 80301, USA.
  • Line MR; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, 91125, USA.
  • Visscher C; Southwest Research Institute, Boulder, CO, 80302, USA.
  • Richardson MR; Rice University, Houston, TX, 77005-1892, USA.
  • Nettelmann N; Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA, 95064, USA.
  • Fortney JJ; Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA, 95064, USA.
  • Barman TS; Lowell Observatory, Flagstaff, AZ, 86001, USA.
  • Stevenson KB; Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL, 60637, USA.
  • Madhusudhan N; Department of Physics and Department of Astronomy, Yale University, New Haven, CT, 06520-8101, USA.
Astrophys J ; 777(1)2013 Nov 01.
Article en En | MEDLINE | ID: mdl-30842681
Neptune-sized extrasolar planets that orbit relatively close to their host stars - often called "hot Neptunes" - are common within the known population of exoplanets and planetary candidates. Similar to our own Uranus and Neptune, inefficient accretion of nebular gas is expected produce hot Neptunes whose masses are dominated by elements heavier than hydrogen and helium. At high atmospheric metallicities of 10-10,000× solar, hot Neptunes will exhibit an interesting continuum of atmospheric compositions, ranging from more Neptune-like, H2-dominated atmospheres to more Venus-like, CO2-dominated atmospheres. We explore the predicted equilibrium and disequilibrium chemistry of generic hot Neptunes and find that the atmospheric composition varies strongly as a function of temperature and bulk atmospheric properties such as metallicity and the C/O ratio. Relatively exotic H2O, CO, CO2, and even O2-dominated atmospheres are possible for hot Neptunes. We apply our models to the case of GJ 436b, where we find that a CO-rich, CH4-poor atmosphere can be a natural consequence of a very high atmospheric metallicity. From comparisons of our results with Spitzer eclipse data for GJ 436b, we conclude that although the spectral fit from the high-metallicity forward models is not quite as good as the best fit obtained from pure retrieval methods, the atmospheric composition predicted by these forward models is more physically and chemically plausible in terms of the relative abundance of major constituents. High-metallicity atmospheres (orders of magnitude in excess of solar) should therefore be considered as a possibility for GJ 436b and other hot Neptunes.
Palabras clave
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Tipo de estudio: Prognostic_studies Idioma: En Revista: Astrophys J Año: 2013 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos
Texto completo
Añadir a Mi BVS
Imprimir
XML
PubMed Links
Buscar en Google

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Tipo de estudio: Prognostic_studies Idioma: En Revista: Astrophys J Año: 2013 Tipo del documento: Article País de afiliación: Estados Unidos Pais de publicación: Estados Unidos