J/A+AS/123/273 Illumination in binaries (Hameury+, 1997)
Illumination in binaries
Hameury J.M., Ritter H.
<Astron. Astrophys. Suppl. Ser. 123, 273 (1997)>
=1997A&AS..123..273H 1997A&AS..123..273H (SIMBAD/NED BibCode)
ADC_Keywords: Accretion
Keywords: accretion, accretion discs - stars: binaries: close - X-rays: stars -
methods: numerical
Description:
We give a simple, but accurate method that can be used to account for
illumination in compact binary systems which have a low-mass
companion, even if spherically symmetric illumination of the secondary
star (not necessarily on the main sequence) is not assumed. This is
done by introducing a multiplicative factor {PHI} in the
Stefan-Boltzmann surface boundary condition, which accounts for the
blocking of the intrinsic secondary flux by X-ray heating of the
photospheric layers. Numerical fits and tables for {PHI} are given for
unperturbed effective temperatures in the range 2500-5600K and logg in
the range 1.0-5.0.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1 22 232875 Function G(x)
table2 52 10304 Coefficients of the fit of the modified
Stefan-Boltzmann surface boundary condition.
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Byte-by-byte Description of file: table1
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Bytes Format Units Label Explanations
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1- 4 F4.2 [cm/s2] logg Surface gravity
6- 9 F4.2 [K] log(Teff) Effective temperature of the unilluminated star
11- 14 F4.2 --- log(1+x) log(1+x) where x is the illuminating flux in
units of the unperturbed stellar flux
16- 22 F7.5 --- log(1/G(x)) -log(G(x)) where G is the fraction of the
interior flux that is not blocked by
illumination
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Byte-by-byte Description of file: table2
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Bytes Format Units Label Explanations
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1- 3 F3.1 --- R2/a Ratio of the secondary radius versus
orbital separation (f2=R2/a)
5- 8 F4.2 [cm/s2] logg Surface gravity
10- 13 F4.2 [K] log(Teff) Effective temperature of the unilluminated star
15- 26 E12.5 --- a1 Coefficient a1 of the polynomial fit of the
modified boundary condition
28- 39 E12.5 --- a2 Coefficient a2 of the polynomial fit of the
modified boundary condition
41- 52 E12.5 --- a3 Coefficient a3 of the polynomial fit of the
modified boundary condition
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Acknowledgements: Jean Marie Hameury
(End) Patricia Bauer [CDS] 24-Sep-1996