J/PASP/108/313 Empirical stellar flux scales (Hall 1996)
On the determination of empirical stellar flux scales
Hall J.C.
<Publ. Astron. Soc. Pac. 108, 313 (1996)>
=1996PASP..108..313H 1996PASP..108..313H
ADC_Keywords: Spectrophotometry
Abstract:
Several studies have appeared in the literature describing methods for
deriving stellar continuum fluxes as simple functions of Johnson color
indices. In previous papers, we have used similar relations to derive
Ca II H & K line core fluxes for dwarf stars on Lowell Observatory's
Solar-Stellar Spectrograph (SSS) program. Our desire is to present our
data, and complementary data from the Mt. Wilson and National Solar
Observatory stellar and solar programs, in terms of physical fluxes.
However, our existing relations break down for mid-K and later stars
and for giant stars, which form an important element of our target
list. In this work I have used a broader range of spectrophotometry
and angular diameters than in our previous work to derive empirical
flux scales for spectral types A to early M, luminosity classes I to
V, and for four color indices, Johnson B-V, V-R, R-I, and Stromgren
b-y. In this paper I describe the methods I used and present the
derived flux scales. I compare the results with those from earlier
studies and present examples of the use of the flux scales. The data
and results are available on the World Wide Web home page. Access
http://www.lowell.edu, select "Lowell staff", and select the author's
home page.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 63 26 Empirical flux scales
table5.dat 67 146 Table of references
table6.dat 64 146 Stellar properties
blanket.dat 89 155 Line blanketing coefficients
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- Bandpass *Bandpass
15- 17 A3 --- CI Color index
19- 24 F6.3 --- C0 *Zeroth-order coefficient of flux scale
26- 32 F7.3 --- C1 *First-order coefficient of flux scale
34- 38 F5.3 --- sigmad Error in dex of flux scale relation
40- 41 I2 % sigmap Error in percent of flux scale relation
43- 48 F6.2 mag CRb *Blue end of CI range
50- 54 F5.2 mag CRr *Red end of CI range
58- 63 A6 --- LC Luminosity classes
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Note on Bandpass:
The continuum flux of a star of color index X in one of the three
bandpasses given in the table is:
F(cont)=(C0+(C1*X))±[sigmad(dex), or ∼sigmap(%)],
with units of mW/m2/(0.1nm). Any pair of coefficients [C0, C1]
applies only to the indicated luminosity classes, and only to the
indicated color range. Due to rapidly decreasing numbers of data points
at the extrema of the color range (resulting from the difficulty of
doing spectrophotometry at those extrema, particularly for K and M
stars), the fits degrade rapidly beyond the indicated ranges.
Note on C0, C1:
These are the coefficients to be entered in a relation of the form
log(F(lambda))=C0+C1(CI), C0 is the zeroth-order coefficient, C1
is the first-order coefficient, and CI is the color index corresponding
to those coefficients.
Note on CRb, CRr:
These fields indicate the range of the particular color index for
which a pair of flux-scale coefficients may be used. A flux-scale
relation should never be applied outside these limits, because of the
many quantities that go into deriving the stellar continuum fluxes, as
well as the rapidly changing and uncertain nature of these quantities
at the color index extrema (e.g.blanketing).
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD Henry Draper Catalogue number
8- 19 A12 --- Name Star name
20- 44 A25 --- rSp *Spectrophotometric references
45- 50 A6 --- rD *Reference for star's angular diameter
52- 63 A12 --- rBl *Reference for blanketing coefficients
64- 67 A4 --- rb-y *Reference for Stromgren b-y index
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Note on rSp, rD, rBl, rb-y:
rSp is the spectrophotometric references for the star.
The main reference used in making the flux scales is listed first.
Other references are listed in parentheses, "()".
Standard stars of Taylor (1984ApJS...54..167T 1984ApJS...54..167T) and
Hayes & Latham (1975, ApJ 197, 593) are listed in angle brackets, "<>".
Abbreviations for all references are as follows:
B76 = Breger (1976ApJS...32....7B 1976ApJS...32....7B)
BEM78 = Barnes, Evans, & Moffett (1978MNRAS.183..285B 1978MNRAS.183..285B)
BL94 = Blackwell & Lynas-Gray (1994A&A...282..899B 1994A&A...282..899B)
BHNT66 = Baschek et al. (1966ZA.....65..418B 1966ZA.....65..418B)
BO65 = Baschek & Oke (1965ApJ...141.1404B 1965ApJ...141.1404B)
CB70 = Crawford & Barnes (1970AJ.....75..946C 1970AJ.....75..946C)
DP71 = Dickens & Penny (1971MNRAS.153..287D 1971MNRAS.153..287D)
HL75 = Hayes & Latham (1975ApJ...197L..55H 1975ApJ...197L..55H)
HM90 = Hauck & Mermilliod (1990A&AS...86..107H 1990A&AS...86..107H)
J66 = Jones 1966; (in Spectral Classification and Multicolor Photometry,
IAU Symp. 24, p.141)
KTK88 = Kharitonov et al. 1988; (The Spectroscopic Catalog of Stars,
Alma-Ata, Nauka)
O67 = Oke (1967ApJ...150..513O 1967ApJ...150..513O)
OC66 = Oke & Conti (1966ApJ...143..134O 1966ApJ...143..134O)
O74 = Oinas (1974ApJS...27..405O 1974ApJS...27..405O)
R69 = Rodriguez (1969, ApJ 5, 125)
S65 = Stromgren & Perry 1965 (Photoelectric uvby photometry for 1217 stars
brighter than V=6.5, mostly of spectral class A, F, & G (Princeton,
Institute for Advanced Study))
S71 = Stickland (1971MNRAS.153..501S 1971MNRAS.153..501S)
SPO71 = Schild, Peterson, & Oke (1971ApJ...166...95S 1971ApJ...166...95S)
T84 = Taylor (1984ApJS...54..259T 1984ApJS...54..259T)
vP76 = van Paradijs (1976A&AS...24...53V 1976A&AS...24...53V)
W65 = Willstrop (1965, MmRAS 69, 83)
W67 = Whiteoak (1967ApJ...150..521W 1967ApJ...150..521W)
WBSB62 = Wildey et al. (1962ApJ...135...94W 1962ApJ...135...94W)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD Star's Henry Draper Catalogue number
9- 18 A10 --- Sp Spectral type and luminosity class
19- 23 F5.2 mas D []?=0. Star's angular diameter
25- 28 F4.2 mas e_D []?=0. Error in D
30- 35 F6.2 mag Vmag V magnitude
37- 42 F6.2 mag B-V Johnson B-V color
44- 49 F6.2 mag V-R []?=9. Johnson V-R color
51- 56 F6.2 mag R-I []?=9. Johnson R-I color
58- 64 F7.3 mag b-y []?=9. Stromgren b-y color
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Byte-by-byte Description of file: blanket.dat
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Bytes Format Units Label Explanations
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1- 4 I4 0.1nm Lambda *Central wavelength of bandpass
6- 11 F6.4 --- C0 Zeroth-order polynomial coefficient
13- 19 F7.4 --- C1 First-order polynomial coefficient
21- 27 F7.4 --- C2 Second-order polynomial coefficient
29- 36 F8.4 --- C3 Third-order polynomial coefficient
38- 45 F8.4 --- C4 Fourth-order polynomial coefficient
47- 52 F6.3 --- sigma Std. dev. of data points about the fit
54- 58 F5.2 mag CRb Bluest color index for the fit
60- 64 F5.2 mag CRr Reddest color index for the fit
65- 68 A4 --- LC0 Luminosity class for C0 (no = blank)
69- 72 A4 --- LC1 Luminosity class for C1 (no = blank)
73- 76 A4 --- LC2 Luminosity class for C2 (no = blank)
77- 80 A4 --- LC3 Luminosity class for C3 (no = blank)
81- 84 A4 --- LC4 Luminosity class for C4 (no = blank)
87- 89 A3 --- CI Color index for coefficient
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Note on Lambda:
The central wavelength of a 50-A wide bandpass to which the
coefficients in the same row are applicable.
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Origin: AAS CD-ROM series, Volume 6, 1996 Lee Brotzman [ADS] 07-May-1996
(End) [CDS] 06-Sep-1996