3D hydrodynamical model atmospheres of metal-poor stars - Evidence for a low primordial Li abundance
dc.contributor.author | Asplund, Martin | en_US |
dc.contributor.author | Nordlund, Ake | en_US |
dc.contributor.author | Trampedach, Regner | en_US |
dc.contributor.author | Stein, Robert F | en_US |
dc.date.accessioned | 2002-12-18 | en_US |
dc.date.accessioned | 2004-05-19T04:52:15Z | en_US |
dc.date.accessioned | 2011-01-05T08:42:14Z | |
dc.date.available | 2004-05-19T04:52:15Z | en_US |
dc.date.available | 2011-01-05T08:42:14Z | |
dc.date.created | 1999 | en_US |
dc.date.issued | 1999 | en_US |
dc.description.abstract | Realistic 3-dimensional (3D), radiative hydrodynamical surface convection simulations of the metal-poor halo stars HD140283 and HD84937 have been performed. Due to the dominance of adiabatic cooling over radiative heating very low atmospheric temperatures are encountered. The lack of spectral lines in these metal-poor stars thus causes much steeper temperature gradients than in classical 1D hydrostatic model atmospheres where the temperature of the optically thin layers is determined by radiative equilibrium. The modified atmospheric structures cause changes in the emergent stellar spectra. In particular, the primordial Li abundances may have been overestimated by 0.2-0.35 dex with 1D model atmospheres. However, we caution that our result assumes local thermodynamic equilibrium (LTE), while the steep temperature gradients may be prone to e.g. over-ionization. | en_US |
dc.format.extent | 125033 bytes | en_US |
dc.format.mimetype | application/pdf | en_US |
dc.identifier.uri | http://hdl.handle.net/1885/40066 | en_US |
dc.identifier.uri | http://digitalcollections.anu.edu.au/handle/1885/40066 | |
dc.language.iso | en_AU | en_US |
dc.subject | convection | en_US |
dc.subject | stars: abundances | en_US |
dc.subject | stars: atmospheres | en_US |
dc.subject | stars: Population II | en_US |
dc.subject | line: formation | en_US |
dc.title | 3D hydrodynamical model atmospheres of metal-poor stars - Evidence for a low primordial Li abundance | en_US |
dc.type | Journal article | en_US |
local.description.refereed | yes | en_US |
local.identifier.citationpages | L17-L20 | en_US |
local.identifier.citationpublication | Astronomy and Astrophysics (Letters to the editors) | en_US |
local.identifier.citationvolume | 346 | en_US |
local.identifier.citationyear | 1999 | en_US |
local.identifier.eprintid | 750 | en_US |
local.rights.ispublished | yes | en_US |
Downloads
Original bundle
1 - 1 of 1