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On the limb darkening, spectral energy distribution, and temperature structure of procyon

Aufdenberg, JP; Ludwig, Hans-Günter LU and Kervella, P (2005) In Astrophysical Journal 633(1). p.424-439
Abstract
We have fit synthetic visibilities from three-dimensional ((COBOLD)-B-5+PHOENIX) and one-dimensional (PHOENIX, ATLAS 12) model stellar atmospheres of Procyon (F5 IV) to high-precision interferometric data from the VLT Interferometer (K band) and from the Mark III interferometer (500 and 800 nm). These data sets provide a test of theoretical wavelength-dependent limb-darkening predictions. The work of Allende Prieto et al. has shown that the temperature structure from a spatially and temporally averaged three-dimensional hydrodynamic model produces significantly less limb darkening at 500 nm relative to the temperature structure of a one-dimensional MARCS model atmosphere with a standard mixing-length approximation for convection. Our... (More)
We have fit synthetic visibilities from three-dimensional ((COBOLD)-B-5+PHOENIX) and one-dimensional (PHOENIX, ATLAS 12) model stellar atmospheres of Procyon (F5 IV) to high-precision interferometric data from the VLT Interferometer (K band) and from the Mark III interferometer (500 and 800 nm). These data sets provide a test of theoretical wavelength-dependent limb-darkening predictions. The work of Allende Prieto et al. has shown that the temperature structure from a spatially and temporally averaged three-dimensional hydrodynamic model produces significantly less limb darkening at 500 nm relative to the temperature structure of a one-dimensional MARCS model atmosphere with a standard mixing-length approximation for convection. Our direct fits to the interferometric data confirm this prediction. A one-dimensional ATLAS 12 model with " approximate overshooting" provides the required temperature gradient. We show, however, that one-dimensional models cannot reproduce the ultraviolet spectrophotometry below 160 nm with effective temperatures in the range constrained by the measured bolometric flux and angular diameter. We find that a good match to the full spectral energy distribution can be obtained with a composite model consisting of a weighted average of 12 one-dimensional model atmospheres based on the surface intensity distribution of a three-dimensional granulation simulation. We emphasize that one-dimensional models with overshooting may realistically represent the mean temperature structure of F-type stars such as Procyon, but the same models will predict redder colors than observed because they lack the multicomponent temperature distribution expected for the surfaces of these stars. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
temperatures), fundamental parameters (colors, stars :, stars : atmospheres, convection, methods : numerical, stars : individual, (Procyon), techniques : interferometric
in
Astrophysical Journal
volume
633
issue
1
pages
424 - 439
publisher
University of Chicago Press
external identifiers
  • wos:000232832500043
  • scopus:29144482613
ISSN
0004-637X
DOI
10.1086/452622
language
English
LU publication?
yes
id
0166aadd-8dcc-4627-a5fc-19ab81783318 (old id 216722)
date added to LUP
2007-08-20 15:47:45
date last changed
2017-09-24 04:24:46
@article{0166aadd-8dcc-4627-a5fc-19ab81783318,
  abstract     = {We have fit synthetic visibilities from three-dimensional ((COBOLD)-B-5+PHOENIX) and one-dimensional (PHOENIX, ATLAS 12) model stellar atmospheres of Procyon (F5 IV) to high-precision interferometric data from the VLT Interferometer (K band) and from the Mark III interferometer (500 and 800 nm). These data sets provide a test of theoretical wavelength-dependent limb-darkening predictions. The work of Allende Prieto et al. has shown that the temperature structure from a spatially and temporally averaged three-dimensional hydrodynamic model produces significantly less limb darkening at 500 nm relative to the temperature structure of a one-dimensional MARCS model atmosphere with a standard mixing-length approximation for convection. Our direct fits to the interferometric data confirm this prediction. A one-dimensional ATLAS 12 model with " approximate overshooting" provides the required temperature gradient. We show, however, that one-dimensional models cannot reproduce the ultraviolet spectrophotometry below 160 nm with effective temperatures in the range constrained by the measured bolometric flux and angular diameter. We find that a good match to the full spectral energy distribution can be obtained with a composite model consisting of a weighted average of 12 one-dimensional model atmospheres based on the surface intensity distribution of a three-dimensional granulation simulation. We emphasize that one-dimensional models with overshooting may realistically represent the mean temperature structure of F-type stars such as Procyon, but the same models will predict redder colors than observed because they lack the multicomponent temperature distribution expected for the surfaces of these stars.},
  author       = {Aufdenberg, JP and Ludwig, Hans-Günter and Kervella, P},
  issn         = {0004-637X},
  keyword      = {temperatures),fundamental parameters (colors,stars :,stars : atmospheres,convection,methods : numerical,stars : individual,(Procyon),techniques : interferometric},
  language     = {eng},
  number       = {1},
  pages        = {424--439},
  publisher    = {University of Chicago Press},
  series       = {Astrophysical Journal},
  title        = {On the limb darkening, spectral energy distribution, and temperature structure of procyon},
  url          = {http://dx.doi.org/10.1086/452622},
  volume       = {633},
  year         = {2005},
}