J/A+A/361/1023 Evolution models for α-enhanced stars (Salasnich+ 2000)
Evolutionary tracks and isochrones for α-enhanced stars.
Salasnich B., Girardi L., Weiss A., Chiosi C.
<Astron. Astrophys., 361, 1023 (2000)>
=2000A&A...361.1023S 2000A&A...361.1023S
ADC_Keywords: Models, evolutionary ; Photometry, UBVRIJKLMNH ; Abundances ;
Effective temperatures
Keywords: stars: evolution - stars: interiors -
stars: Hertzsprung-Russel (HR) and C-M diagrams
Abstract:
We present four large sets of evolutionary tracks for stars with
initial chemical compositions [Y=0.250, Z=0.008], [Y=0.2773, Z=0.019],
[Y=0.320, Z=0.040] and [Y=0.390, Z=0.070] and enhancement of α
elements with respect to the solar pattern. The major improvement with
respect to previous similar calculations is that we use consistent
opacities - i.e. computed with the same chemical composition as
adopted in the stellar models - over the whole relevant range of
temperatures. For the same initial chemical compositions [Y, Z] and
otherwise identical input physics we present also new evolutionary
sequences with solar-scaled mixtures of abundances. Based on these
stellar models we calculate the corresponding sets of isochrones both
in the Johnson-Cousins UBVRIJHK and HST/WFPC2 photometric systems.
Furthermore, we derive integrated magnitudes, colours and
mass-to-light ratios for ideal single stellar populations with total
mass equal to 1M☉ Finally, the major changes in the tracks,
isochrones, and integrated magnitudes and colours passing from
solar-scaled to α-enhanced mixtures are briefly outlined.
Retrieval of the complete data set is possible via the www page
http://pleiadi.pd.astro.it .
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
mstracks.dat 186 19869 Tracks computed from the ZAMS on
hbtracks.dat 186 5732 Tracks evolved from the ZAHB on
isostmag.dat 172 87660 Isochrones in the HST/WFPC2 STMAG system
isovega.dat 171 87660 Isochrones in the HST/WFPC2 VEGAMAG system
isojcmag.dat 145 87660 Isochrones in the Johnson-Cousins system
sspstmag.dat 108 536 Integrated magnitudes in the HST/WFPC2 STMAG
system
sspvega.dat 108 536 Integrated magnitudes in the HST/WFPC2 VEGAMAG
system
sspjcmag.dat 87 536 Integrated colours in the Johnson-Cousins system
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See also:
J/A+A/311/361 : Evolution models of elliptical galaxies. II. (Tantalo+, 1996)
J/A+A/335/823 : Evolution models of elliptical galaxies. III. (Tantalo+ 1998)
J/A+AS/100/647 : Evolutionary Sequences. II. (Bressan+ 1993)
J/A+AS/104/365 : Evolutionary sequences. III. (Fagotto+ 1994)
J/A+AS/105/29 : Evolutionary sequences. IV. (Fagotto+ 1994)
J/A+AS/105/39 : Evolutionary sequences. V. (Fagotto+ 1994)
J/A+AS/117/113 : Evolutionary sequences. VI. (Girardi+ 1996)
J/A+AS/106/275 : Theoretical isochrones (Bertelli+ 1994)
J/A+AS/141/371 : Low-mass stars evolutionary tracks+isochrones (Girardi+, 2000)
Byte-by-byte Description of file: mstracks.dat hbtracks.dat
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Bytes Format Units Label Explanations
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1 A1 --- flag [as] a: alpha-enhanced, s: solar-scaled
3- 7 F5.2 solMass Mass Initial star mass
9- 13 F5.3 --- Z Initial metallicity
15- 19 F5.3 --- Y Initial helium abundance
22- 32 E11.5 yr Age Stellar age
34- 39 F6.3 [solLum] logL logarithm of surface luminosity
42- 46 F5.3 [K] logTeff logarithm of effective temperature
48- 53 F6.3 [cm/s2] logg logarithm of surface gravity (in cgs units)
56- 60 F5.3 [K] logTc logarithm of central temperature
63- 67 F5.3 [g/cm3] logrho logarithm of central density (in cgs units)
70- 74 F5.3 --- XcYc Mass fraction of either hydrogen (up to the
central H-exhaustion) or helium (later
stages) in the stellar centre
76- 82 E7.2 --- XcC Mass fraction of carbon in the stellar centre
84- 90 E7.2 --- XcO Mass fraction of oxygen in the stellar centre
92- 97 F6.4 --- Qconv Fractional mass of the convective core
99-104 F6.4 --- Qdisc Fractional mass of the first mesh point where
the chemical composition differs from the
surface value
106-111 F6.3 [solLum] logLH logarithm of the total luminosity provided by
H-burning reactions
113-118 F6.4 --- Q1H Fractionary mass of the inner boundary of the
H-rich region
120-125 F6.4 --- Q2H Fractionary mass of the outer boundary of the
H-burning region
127-132 F6.3 [solLum] logLHe logarithm of the total luminosity provided by
He-burning reactions (2)
134-139 F6.4 --- Q1He Fractionary mass of the inner boundary of the
He-burning region
141-146 F6.4 --- Q2He Fractionary mass of the outer boundary of the
He-burning region
149-153 F5.3 [solLum] logLC logarithm of the total luminosity provided by
C-burning reactions (2)
155-160 F6.3 [solLum] logLnu logarithm of the total luminosity lost by
neutrinos (2)
163-168 F6.4 --- QTmax Fractionary mass of the point with the highest
temperature inside the star
171-178 A8 --- Stage Label indicating particular evolutionary
stages (see the paper for details) (G1)
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Note (2): a null value indicates negligible energy generation by those reactions
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Byte-by-byte Description of file: isostmag.dat isovega.dat
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Bytes Format Units Label Explanations
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1 A1 --- flag [as] (a: alpha-enhanced, s: solar-scaled)
3- 9 F7.5 --- Z Metallicity
11- 19 E9.3 yr Age Age
21- 25 F5.2 [yr] log(Age) logarithm of the age
27- 37 F11.8 solMass Mini Initial mass of the star
39- 45 F7.4 solMass Mact Actual mass of the star (1)
47- 53 F7.4 solLum logL logarithm of surface luminosity
55- 60 F6.4 [K] logTe logarithm of effective temperature
62- 68 F7.4 [cm/s2] logG logarithm of surface gravity
70- 75 F6.3 mag Mbol Absolute bolometric magnitude
77- 82 F6.3 mag f170w Absolute magnitude in the F170W pass-band
84- 89 F6.3 mag f218w Absolute magnitude in the F218W pass-band
91- 96 F6.3 mag f255w Absolute magnitude in the F255W pass-band
98-103 F6.3 mag f300w Absolute magnitude in the F300W pass-band
105-110 F6.3 mag f336w Absolute magnitude in the F336W pass-band
112-117 F6.3 mag f439w Absolute magnitude in the F439W pass-band
119-124 F6.3 mag f450w Absolute magnitude in the F450W pass-band
126-131 F6.3 mag f555w Absolute magnitude in the F555W pass-band
133-138 F6.3 mag f606w Absolute magnitude in the F606W pass-band
140-145 F6.3 mag f702w Absolute magnitude in the F702W pass-band
147-152 F6.3 mag f814w Absolute magnitude in the F814W pass-band
154-159 F6.3 mag f850lw Absolute magnitude in the F850LW pass-band
161-171 F11.8 --- Flum Indefinite integral of the Salpeter IMF
by number (see the paper for more details)
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Note (1): i.e., the mass obtained considering the previous history of mass-loss
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Byte-by-byte Description of file: isojcmag.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- flag [as] (a: alpha-enhanced, s: solar-scaled)
3- 9 F7.5 --- Z Metallicity
11- 19 E9.3 yr Age Age
21- 25 F5.2 [yr] log(Age) logarithm of the age
27- 37 F11.8 solMass Mini Initial mass of the star
39- 45 F7.4 solMass Mact Actual mass of the star (1)
47- 53 F7.4 solLum logL logarithm of surface luminosity
55- 60 F6.4 [K] logTe logarithm of effective temperature
62- 68 F7.4 [cm/s2] logG logarithm of surface gravity
70- 75 F6.3 mag Mbol Absolute bolometric magnitude
77- 82 F6.3 mag UMag Absolute magnitude in the U pass-band
84- 89 F6.3 mag BMag Absolute magnitude in the B pass-band
91- 96 F6.3 mag VMag Absolute magnitude in the V pass-band
98-103 F6.3 mag RMag Absolute magnitude in the R pass-band (Cousins)
105-110 F6.3 mag IMag Absolute magnitude in the I pass-band (Cousins)
112-117 F6.3 mag JMag Absolute magnitude in the J pass-band
119-125 F7.3 mag HMag Absolute magnitude in the H pass-band
127-133 F7.3 mag KMag Absolute magnitude in the K pass-band
135-145 F11.8 --- Flum Indefinite integral of the Salpeter IMF
by number (see the paper for more details)
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Note (1): i.e., the mass obtained considering the previous history of mass-loss
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Byte-by-byte Description of file: sspstmag.dat sspvega.dat
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Bytes Format Units Label Explanations
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1 A1 --- flag [as] (a: alpha-enhanced, s: solar-scaled)
3- 8 F6.4 --- Z Metallicity
10- 17 E8.2 yr Age Age
19- 24 F6.3 mag Mbol Integrated bolometric magnitude (G2)
26- 31 F6.3 mag f170w Integrated magnitude in the F170W pass-band (G2)
33- 38 F6.3 mag f218w Integrated magnitude in the F218W pass-band (G2)
40- 45 F6.3 mag f255w Integrated magnitude in the F255W pass-band (G2)
47- 52 F6.3 mag f300w Integrated magnitude in the F300W pass-band (G2)
54- 59 F6.3 mag f336w Integrated magnitude in the F336W pass-band (G2)
61- 66 F6.3 mag f439w Integrated magnitude in the F439W pass-band (G2)
68- 73 F6.3 mag f450w Integrated magnitude in the F450W pass-band (G2)
75- 80 F6.3 mag f555w Integrated magnitude in the F555W pass-band (G2)
82- 87 F6.3 mag f606w Integrated magnitude in the F606W pass-band (G2)
89- 94 F6.3 mag f702w Integrated magnitude in the F702W pass-band (G2)
96-101 F6.3 mag f814w Integrated magnitude in the F814W pass-band (G2)
103-108 F6.3 mag f850lw Integrated magnitude in the F850LW pass-band (G2)
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Byte-by-byte Description of file: sspjcmag.dat
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Bytes Format Units Label Explanations
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1 A1 --- flag [as] a: alpha-enhanced, s: solar-scaled
3- 8 F6.4 --- Z Metallicity
10- 17 E8.2 yr Age Age
19- 23 F5.3 solMass Mtot Total mass
25- 30 F6.3 --- M/Lv Mass-to-light ratio
32- 36 F5.3 mag Mv Integrated absolute V magnitude (G2)
38- 43 F6.3 mag B-V Integrated B-V colour index (G2)
45- 50 F6.3 mag U-B Integrated U-B colour index (G2)
52- 57 F6.3 mag BC Bolometric correction
59- 63 F5.3 mag V-R Integrated V-R colour index (G2)
65- 69 F5.3 mag V-I Integrated V-I colour index (G2)
71- 75 F5.3 mag V-J Integrated V-J colour index (G2)
77- 81 F5.3 mag V-H Integrated V-H colour index (G2)
83- 87 F5.3 mag V-K Integrated V-K colour index (G2)
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Global notes:
Note (G1): Particular evolutionary stages:
ZAMS: initial evolutionary stage
ZAHB: initial evolutionary stage
Te-M: local maxima of Teff
Te-m: local minima of Teff
L-M: local maxima of L
L-m: local minima of L
Xc=0: exhaustion of central hydrogen
Yc=0: exhaustion of central helium
Bhe: highest Teff during the He-burning of intermediate-mass star
LpT: lowest L during the He-burning of intermediate-mass star
Brg: base of the first ascent of the red giant branch
Tip: tip of the first ascent of the red giant branch
1tp: maximum L immediately preceding a thermal pulse
1TP: beginning of the thermally pulsing AGB phase
Cb: stage of C-ignition in the cases the AGB phase do not occur
AGBt: end of AGB phase
BHeb: begin of the core helium burning phase
EHeb: end of the core helium burning phase
RGBb: base of the RGB
RGBt: tip of RGB phase
TO: turn-off point, i.e. the point of highest Teff during
the core-H burning phase
F: Final model
Note (G2): The integrated colours or magnitudes are tabulated as a function of
age. They are computed assuming a simple Salpeter IMF normalized to
1M☉, and with a low-mass cutoff such as to reproduce a
mass-to-light ratio of M/L_V=0.19 at an age of 10^8yr,
for the Z=0.008 solar-scaled case. Therefore, they represent the
luminosity evolution of SSPs of initial mass equal to 1M☉.
See the paper for more details.
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Acknowledgements: Leo Girardi
History:
An updated version of this database, containing extensions
and a lot of additional data, is being kept at the URL
http://pleiadi.pd.astro.it
(End) Patricia Bauer [CDS] 28-Nov-2000