J/AJ/119/1424 Color-temperature relations of M giants (Houdashelt+, 2000)
Synthetic spectra and color-temperature relations of M giants
Houdashelt M.L., Bell R.A., Sweigart A.V., Wing R.F.
<Astron. J. 119, 1424 (2000)>
=2000AJ....119.1424H 2000AJ....119.1424H
ADC_Keywords: Colors ; Models, atmosphere ; Photometry, Cousins ;
Photometry, UBVRI ; Stars, M-type
Keywords: infrared radiation - stars: atmospheres - stars: evolution - stars:
fundamental parameters - stars: late-type
Abstract:
As part of a project to model the integrated spectra and colors of
elliptical galaxies through evolutionary synthesis, we have refined
our synthetic spectrum calculations of M giants. After critically
assessing three effective temperature scales for M giants, we adopted
the relation of Dyck et al. for our models. Using empirical spectra of
field M giants as a guide, we then calculated MARCS stellar atmosphere
models (Gustafsson et al. 1975; Bell et al. 1976) and SSG synthetic
spectra (Bell & Gustafsson 1978; Gustafsson & Bell 1979) of
these cool stars, adjusting the band absorption oscillator strengths
of the TiO bands to better reproduce the observational data. The
resulting synthetic spectra are found to be in very good agreement
with the K-band spectra of stars of the appropriate spectral type
taken from Kleinmann & Hall (1986) as well. Spectral types estimated
from the strengths of the TiO bands and the depth of the band head of
CO near 2.3 µm quantitatively confirm that the synthetic spectra
are good representations of those of field M giants. The broadband
colors of the models match the field relations of K and early-M giants
very well; for late-M giants, differences between the field star and
synthetic colors are probably caused by the omission of spectral lines
of VO and H2O in the spectrum synthesis calculations. Here, we
present four grids of K-band bolometric corrections and colors -
Johnson U-V and B-V, Cousins V-R and V-I, Johnson-Glass V-K, J-K, and
H-K, and CIT/CTIO V-K, J-K, H-K, and CO - for models having 3000 K
≤ Teff ≤ 4000 K and -0.5 ≤ log(g) ≤ 1.5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 123 220 Calibrated color-temperature relations of
M giants
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See also:
J/AJ/119/1448 : Improved properties for cool stars (Houdashelt+, 2000)
Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 4 I4 K Temp Effective temperature
8- 12 F5.2 [cm/s2] Log(g) Log of the surface gravity
15- 19 F5.2 [Sun] [Fe/H] Log of the iron to hydrogen abundance
relative to solar
23- 27 A5 --- SpType Spectral classification
31- 35 F5.3 mag (U-B) The Johnson-Cousins U-B color
(Bessel 1990PASP..102.1181B 1990PASP..102.1181B)
39- 43 F5.3 mag (B-V) The Johnson-Cousins B-V color
(Bessel 1990PASP..102.1181B 1990PASP..102.1181B)
47- 51 F5.3 mag (V-R) The Johnson-Cousins V-R color
(Bessel 1990PASP..102.1181B 1990PASP..102.1181B)
55- 59 F5.3 mag (V-I) The Johnson-Cousins V-I color
(Bessel 1990PASP..102.1181B 1990PASP..102.1181B)
63- 67 F5.3 mag (V-K) The Johnson-Glass V-K color
(Bessel & Brett 1988PASP..100.1134B 1988PASP..100.1134B)
71- 75 F5.3 mag (J-K) The Johnson-Glass J-K color
(Bessel & Brett 1988PASP..100.1134B 1988PASP..100.1134B)
79- 83 F5.3 mag (H-K) The Johnson-Glass H-K color
(Bessel & Brett 1988PASP..100.1134B 1988PASP..100.1134B)
87- 91 F5.3 mag (V-K)c The CIT-CTIO V-K color
95- 99 F5.3 mag (J-K)c The CIT-CTIO V-K color
103-107 F5.3 mag (H-K)c The CIT-CTIO V-K color
111-115 F5.3 mag CO The CIT-CTIO CO filter magnitude without
color correction (Frogel+ 1978ApJ...220...75F 1978ApJ...220...75F)
119-123 F5.3 mag BC K band bolometric correction (1)
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Note (1): BCV = BC - (V-K)
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History:
From AJ electronic edition
References:
Bell, R. A., Eriksson, K., Gustafsson, B., & Nordlund, A. 1976, A&AS,
23, 37 (1976A&AS...23...37B 1976A&AS...23...37B)
Bell, R. A., & Gustafsson, B. 1978, A&AS, 34, 229 (1978A&AS...34..229B 1978A&AS...34..229B)
Gustafsson, B. Bell, R. A., Eriksson, K. Nordlund, A. 1975, A&A, 42 407
(1975A&A....42..407G 1975A&A....42..407G)
Gustafsson, B. & Bell, R. A. 1979, A&A, 74, 313 (1979A&A....74..313G 1979A&A....74..313G)
Kleinmann, S. G., & Hall, D. N. B. 1986, ApJS, 62, 501 (1986ApJS...62..501K 1986ApJS...62..501K)
(End) Greg Schwarz [AAS] 17-Apr-2000