VI/78 Theoretical Stellar Flux Spectra for F- to K-type Stars (Buser+ 1992)
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A Library of Theoretical Stellar Flux Spectra. I.
Synthetic UBVRI photometry and the metallicity scale for F- to K-type stars
BUSER R., KURUCZ R.L.
=1992A&A...264..557B
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ADC_Keywords: Models, atmosphere ; Stars, late-type ;
Description:
In conjunction with Kurucz' (1979a,b) models for O to G stars,
the present models for F- to K- stars provide an extensive,
quasi-homogeneous grid of low-resolution theoretical flux
spectra for a significant range in stellar parameters covering
mostly of the observed HR diagram.
The file bklate.dat contains 242 theoretical model atmosphere
flux distributions for late-type stars. These flux distributions
were calculated by Buser & Kurucz in 1983-5 using published and
unpublished models by Gustafsson and his associates. Please
refer to the publication (A&A 264, 447) for a full description
of the calculations and a discussion of synthetic UBVRI photometry
computed from these models.
The models cover the following ranges in the parameter space:
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number fraction of hydrogen xH =0.9 all models
turbulent velocity [km/s] vturb =2.00 234 models
vturb =5.00 8 models
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3750 <= Teff <= 6000 (K)
0.75 <= log.g <= 5.25 (cm/s/s)
-3.00 <= [Fe/H] <= 0.50 (dex)
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Notice that the model sequence does NOT strictly follow an
orderly pattern in parameter space, because the present
file was composed from several original files having their
individual parameter sequences. The last model (#242) is
the solar model.
Note that the present file still contains 8 models (out of a total
of 242) which have turbulent velocities vturb=5.00 km/s, but
whose flux distributions have n o t actually been computed
for this value of vturb (=5.00 km/s). Hence, for these models,
the flux distributions given in the present file are erroneous
and should not be used at all. It is suggested that the user
d e l e t e them from the file altogether; for the user's
convenience, these models are marked on the accompanying list.
References:
Kurucz R.L., 1979a, ApJS 40, 1 (CDS Catalogue VI/39)
Kurucz R.L., 1979b, in: "Problems of Calibration of Multicolor
Photometric Systems", Philip A.G.Davis (ed.),
Dudley Obs. Rep. 14, p. 363
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
bklate.dat 80 24001 The Library of Theoretical Fluxes
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Structure of File bklate.dat:
The data come in a SINGLE ASCII FILE, as follows:
* The first block of data gives the wavelengths in nanometers
(1 nm = 1.0e-09 m) for the 342 wavelength points on the
standard Kurucz grid for which fluxes have been computed.
The format is (8f10.1).
* The next block of data gives the parameter data for each model
listed as follows:
+first record: model identification:
nmodel,iteff,glog,xscale,vturb,xh
where nmodel....running number of model,
iteff.....effective temperature,
glog......log g (surface gravity),
xscale....[A/H] (logarithmic metal abundance),
vturb.....turbulent velocity,
xh........number fraction of hydrogen.
The format is (i5,i6,4f6.2).
+Following records: line blanketed fluxes and continuum fluxes:
hnu,cont
where hnu.......line blanketed emergent surface flux
moment in erg/s/cm/cm/Hz,
cont......continuum surface flux moment
in erg/s/cm/cm/Hz.
The format is (7e11.4).
Note about the Units:
HNU and CONT are expressed as flux moments, and are given in
the units ergs/s/cm/cm/Hz (SI: mW/m/m/Hz). Hence FLAMBDA, in
units ergs/s/cm/cm/Angstrom, must be calculated from HNU
using the equation
FLAMBDA=0.4*HNU*c/LAMBDA/LAMBDA, (1)
where
c=2.997925e17.......is the velocity of light
and
LAMBDA..............is the wavelength in nanometers
(as tabulated at the beginning of the
file BKLATE.DAT).
The numerical factor of 0.4 (=4*0.1) in equation (1) above
comes from the conversion of the flux moment into flux (*4)
and from the conversion of flux per nanometer into flux per
Angstrom (*0.1).
NOTICE however that FLAMBDA still is a surface flux; therefore,
calculations of absolute luminosities for the BKLATE models
require additional assumptions about the radii of the stars
represented by the models.
Program to read bklate.dat:
Program bklateread
c
c Roland Buser
c Space Telescope Science Institute, Baltimore, U.S.A.
c and
c University of Basel, Switzerland
c
c August 1986, update April 1994
c
c The following program reads the file BKLATE.DAT of model atmosphere
c flux distributions for late-type stars; the program also
c generates a listing of parameter values for all the models in
c the flux file.
c
dimension wave(342),hnu(342),cont(342)
open(unit=5,name='bklate.dat',status='old')
* open(unit=6,name='bklatelist.dat',status='new')
write(6,4)
read(5,1)wave
do 10 i=1,242
read(5,2)nmodel,iteff,glog,xscale,vturb,xh
write(6,2)nomdel,iteff,glog,xscale,vturb,xh
read(5,3)hnu,cont
10 continue
1 format(8f10.1)
2 format(i5,i6,4f6.2)
3 format(7e11.4)
4 format(1h1,3h #,t8,4hTEFF,t13,5hlog g,t19,5h[A/H],t25,5hvturb,
1t33,2hxH//)
close(unit=5)
close(unit=6)
stop
end
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(End) Roland Buser [Astron. Inst. Basel] 17-Feb-1995