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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
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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
American Astronomical Society
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
2016-04-01 16:13:32
date last changed
2022-12-12 17:21:56
@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}},
  keywords     = {{temperatures); fundamental parameters (colors; stars :; stars : atmospheres; convection; methods : numerical; stars : individual; (Procyon); techniques : interferometric}},
  language     = {{eng}},
  number       = {{1}},
  pages        = {{424--439}},
  publisher    = {{American Astronomical Society}},
  series       = {{Astrophysical Journal}},
  title        = {{On the limb darkening, spectral energy distribution, and temperature structure of procyon}},
  url          = {{http://dx.doi.org/10.1086/452622}},
  doi          = {{10.1086/452622}},
  volume       = {{633}},
  year         = {{2005}},
}