J/A+A/325/693 Quantitative spectral classification (Malyuto+ 1997)
Quantitative spectral classification based on photoelectric spectrum
scanner measurements of F-K stars
Malyuto V., Schmidt-Kaler T.
<Astron. Astrophys. 325, 693 (1997)>
=1997A&A...325..693M 1997A&A...325..693M
ADC_Keywords: MK spectral classification ; Spectrophotometry
Keywords: stars: fundamental parameters, classification
Description:
New criteria of quantitative spectral classification have been
introduced and the method of stepwise linear regression to these
criteria for quantitative spectral classification of F-K stars has
been applied to the Bochum photoelectric spectra (resolution 10A).
Table 4 contains the averaged values of the classification criteria
(indices) for 54 stars used in our analysis.
Each measurement in our analysis refers to an area confined by the
border wavelengths for an interval, the spectral energy distribution
and the zero level. We chose the intervals for measurements in a such
way that the sensitivity to spectral and/or luminosity effects were
different for two adjacent or near-by intervals. The ratios of
measurements in such intervals may then serve as classification
criteria (indices) with minimum contamination by interstellar
extinction. Table 2 contains the border wavelengths for the intervals
with indications of the principal measured features. Table 3 contains
the list of classification indices. Table 2. The border wavelengths
for the intervals in Angstroems.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4 45 54 Measurements of the indices 1-6
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Byte-by-byte Description of file: table4
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Bytes Format Units Label Explanations
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1- 6 I6 --- HD HD number
7- 12 F6.3 --- I1 ?=9.999 Index 1 in relative intensity (1)
13- 18 F6.3 --- I2 ?=9.999 Index 2 in relative intensity (1)
19- 24 F6.3 --- I3 ?=9.999 Index 3 in relative intensity (1)
25- 30 F6.3 --- I4 ?=9.999 Index 4 in relative intensity (1)
31- 36 F6.3 --- I5 ?=9.999 Index 5 in relative intensity (1)
37- 42 F6.3 --- I6 ?=9.999 Index 6 in relative intensity (1)
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Note (1): See table2 and table3 for the definitions of the indices.
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Table 2: The border wavelengths for the intervals in Angstroems
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Interval Left Right Dλ Prominent features (λ in A)
No. side side
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1 3660 3700 40 3680, FeI; 3685, TiII; 3687, FeI
2 3700 3780 80 3720, 3735, 3749, FeI; 3750, 3771, HI
3 4120 4215 95 4132, FeI; 4176-200, FeI,CN; 4215, CN
4 4215 4280 65 4227, CaI; 4253, CrI, FeI; 4272, FeI
5 4280 4320 40 4290, CrI; 4299, CH, FeI; 4308, CH, FeI
6 4320 4360 40 4340, HI
7 4515 4575 60 4528, FeI; 4549, FeII, TiII
8 4575 4635 60 4582, CaI, FeI; 4602-3, CrI, FeI
9 5125 5245 120 5134-52, FeI; 5172, MgI; 5210, CrI; 5227-33, FeI
10 5245 5290 45 5270, FeI, CaI
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Table 3: The classification indices (ratios of measurements in the intervals)
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Indice Interval No. Wavelengths for Difference of Criterion (%)
No. (from Table 2) intervals in A mean wavelengths r.m.s.error
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1 1/2 (3660-3700)/(3700-3780) 60 3.4±1.2
2 3/4 (4120-4215)/(4215-4280) 80 1.8±0.6
3 4/6 (4215-4280)/(4320-4360) 92 1.0±0.4
4 5/6 (4280-4320)/(4320-4360) 40 2.0±0.7
5 7/8 (4515-4575)/(4575-4635) 90 0.7±0.2
6 9/10 (5125-5245)/(5245-5290) 83 0.7±0.3
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Acknowledgements: Valeri Maljuto
(End) Patricia Bauer [CDS] 18-Dec-1996