A Bag of Stellar Tracks and Isochrones...
last modification: 26 Nov 2009
This database contains the grid of evolutionary tracks described in Pietrinferni, Cassisi, Salaris & Castelli (2004, ApJ, 612, 168).
The models do not include gravitational settling, radiative acceleration, rotational mixing, but otherwise they are based on up-to-date physics, as detailed in the quoted paper, and account for core convective overshooting during the H-burning phase.
We strongly encourage people interested in a specific set of evolutionary tracks (not yet available in this database) to contact us, either by e_mail or by compiling the request form (present in this web site). We'll try to perform these computations within a week upon receiving the request.
We have presently stored evolutionary models with the following chemical compositions:
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The values Z=0.0198 (zsun) and Y=0.2734 (ysun) correspond to the abundances obtained from the calibration of the solar model (for more details we refer to Pietrinferni et al. 2004).
All models have been computed using a scaled solar distribution (Grevesse & Noels 1993) for the heavy elements, and include mass loss according to the Reimers (1975) law. The mass loss efficiency parameter eta has been fixed to eta=0.4 for the full set of models. To allow investigations about the effect of different mass loss efficiencies on the properties of individual stars and stellar populations, we have computed an additional set of low-mass models - for the same chemical compositions - using eta=0.2. We have verified that the evolution of more massive stars is not appreciably affected when changing eta= from 0.4 down to 0.2. This enables one to use consistently in population synthesis studies the low-mass models computed with eta=0.2 together with the more massive ones computed with eta=0.4, to mimick the effect of a global reduction of eta= from 0.4 to 0.2.
The mass range goes from 1.1Mo to 10.0Mo. Please note that the mass spacing is suitably small, although larger than the one adopted for canonical models.
Each file contains:
in the fifth line - 1) the number of evolutionary points, 2) the global metallicity [M/H], 3) the abundance by mass of metals (Z), 4) the initial He abundance (Y), 5) the inital mass (in solar unit); starting from the ninth line the following quantities are listed:
1 column) the logarithm of the age in years; 2 column) the actual mass in solar unit; 3 column) the logarithm of the surface luminosity in solar unit; 4 column) the logarithm of the effective temperature (K); 5 column) the visual absolute magnitude; 6 column) the (B-V) colour; 7 column) the (U-B) colour; 8 column) the (V-I) colour; 9 column) the (V-R) colour; 10 column) the (V-J) colour; 11 column) the (V-K) colour; 12 column) the (V-L) colour; 13 column) the (H-K) colour;from the Zero Age main Sequence until the first few thermal pulses. For details about the adopted color - effective temperature relations and bolometric correction scale we refer to the quoted reference.
The coding of the file names is as follows:
abcdZedfYghio.nor_c03hbs
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| evolutionary track for a model with --> initial mass = ab.cd Mo
--> metallicity Z= e.d x 10^(-f)
--> initial He abundance Y = 0.ghi
The suffix "o" denotes models computed by accounting overshooting during the central H-burning phase. The suffix "nor" indicates that the evolutionary sequence has been "reduced" to a suitable number of points. This has been accomplished by fixing some key stage along the evolutionary path, and distributing for each track the same number of points between two consecutive stages. This allows a straightforward interpolation for producing isochrones of a given age, and for determining tracks and isochrones for other metallicities within the range spanned by the computed grid of models.
Example: 0130z402y303o.nor_c03hbs ---> 1.30 Mo Non canonical model with Z=4.0E-2 and Y=0.303 |
The full set of evolutionary tracks can be also downloades as a single compressed tar archive.
The whole set of evolutionary models has been also transferred from the theoretical plane to the Advanced Camera for Survey (ACS), WFC2 and WFC3 - on board of HST - Vega-mag, Stroemgren and Sloan systems. Each set of models can be downloaded as a single compressed tar archive. Each file contains:
on the fifth line - 1) the number of evolutionary points, 2) the global metallicity [M/H], 3) the abundance by mass of metals (Z), 4) the initial He abundance (Y), 5) the inital mass (in solar unit); starting from the ninth line the following quantities are listed, from the Zero Age Main Sequence until the first few thermal pulses (for masses larger than 0.7Mo):
ACS system
1 column) the logarithm of the age in years; 2 column) the actual mass in solar units; 3 column) the logarithm of the surface luminosity in solar units; 4 column) the logarithm of the effective temperature (K); 5 column) the F435W magnitude; 6 column) the F475W magnitude; 7 column) the F555W magnitude; 8 column) the F606W magnitude; 9 column) the F625W magnitude; 10 column) the F775W magnitude; 11 column) the F814W magnitude;
Stroemgren system
1 column) the logarithm of the age in years; 2 column) the actual mass in solar units; 3 column) the logarithm of the surface luminosity in solar unit; 4 column) the logarithm of the effective temperature (K); 5 column) the y absolute magnitude (My); 6 column) the (u-b) colour; 7 column) the (u_0-b) colour; 8 column) the (b-y) colour; 9 column) the m_1 colour index; 10 column) the c_1 colour index; 11 column) the c_1_0 colour index; 12 column) the H_beta colour index; 13 column) the hk colour index;
Sloan system
1 column) the logarithm of the age in years; 2 column) the actual mass in solar units; 3 column) the logarithm of the surface luminosity in solar unit; 4 column) the logarithm of the effective temperature (K); 5 column) the g absolute magnitude (Mg); 6 column) the (u-g) colour; 7 column) the (g-r) colour; 8 column) the (r-i) colour; 9 column) the (i-z) colour index
Walraven system
1 column) the logarithm of the age in years; 2 column) the actual mass in solar units; 3 column) the logarithm of the surface luminosity in solar unit; 4 column) the logarithm of the effective temperature (K); 5 column) the V absolute magnitude (Mv); 6 column) the (V-B) colour; 7 column) the (B-U) colour; 8 column) the (U-W) colour; 9 column) the (B-L) colour; 10 column) the (L-U) colour index
WFC2 system
1 column) the logarithm of the age in years; 2 column) the actual mass in solar units; 3 column) the logarithm of the surface luminosity in solar units; 4 column) the logarithm of the effective temperature (K); 5 column) the F122W magnitude; 6 column) the F130lp magnitude; 7 column) the F160W magnitude; 8 column) the F165lp magnitude; 9 column) the F170W magnitude; 10 column) the F185W magnitude; 11 column) the F218W magnitude; 12 column) the F255W magnitude; 13 column) the F300W magnitude; 14 column) the F336W magnitude; 15 column) the F380W magnitude; 16 column) the F439W magnitude; 17 column) the F450W magnitude; 18 column) the F555W magnitude; 19 column) the F606W magnitude; 20 column) the F622W magnitude; 21 column) the F675W magnitude; 22 column) the F702W magnitude; 23 column) the F791W magnitude; 24 column) the F814W magnitude; 25 column) the F850lp magnitude;
WFC3(UVIS) system
1 column) the logarithm of the age in years; 2 column) the actual mass in solar units; 3 column) the logarithm of the surface luminosity in solar units; 4 column) the logarithm of the effective temperature (K); 5 column) F218W magnitude; 6 column) F225W magnitude; 7 column) F275W magnitude; 8 column) F336W magnitude; 9 column) F390W magnitude; 10 column) F438W magnitude; 11 column) F475W magnitude; 12 column) F555W magnitude; 13 column) F606W magnitude; 14 column) F625W magnitude; 15 column) F775W magnitude; 16 column) F814W magnitude;
WFC3(IR) system
1 column) the logarithm of the age in years; 2 column) the actual mass in solar units; 3 column) the logarithm of the surface luminosity in solar units; 4 column) the logarithm of the effective temperature (K); 5 column) F098M magnitude; 6 column) F105W magnitude; 7 column) F110W magnitude; 8 column) F125W magnitude; 9 column) F126N magnitude; 10 column) F127M magnitude; 11 column) F128N magnitude; 12 column) F130N magnitude; 13 column) F132N magnitude; 14 column) F139M magnitude; 15 column) F140W magnitude; 16 column) F153M magnitude; 17 column) F160W magnitude; 18 column) F164N magnitude; 19 column) F167N magnitude;
The coding of the file names is the same adopted for the tracks in the Johnson-Cousins photometric system.
For details about the adopted colour - effective temperature relations, bolometric correction scale and the adopted zero point photometric calibration in the ACS system, we refer to:
Bedin, R.L., Cassisi, S., Piotto, G., Castelli, F., Salaris, M., Momany, Y. & Pietrinferni, A. 2005, MNRAS, 357, 1038.
All colour indices in the Stroemgren system have been normalized on Vega, but the hk index, that has been normalized on HD83373 assuming T_eff=10550K, log(g)=4.0, [M/H]=0.0 and v_t= 2.0 km/s. The index 0 means reduction to airmass equal to 0.0 from indices computed for airmasses equal to 1 and 2 (see Kurucz, R.L. 1979, ApJS, 40, 1).
Details on the transformation to the Sloan system can be found in Marconi et al. (2006, MNRAS 371, 1503).
For some general information about the adopted colour - effective temperature relations, bolometric correction scale, we refer to:
Pietrinferni, Cassisi, Salaris & Castelli (2006, ApJ, 642, 797)
Castelli, F. & Kurucz, R.L. 2006, A&A, 454, 333
and to http://wwwuser.oat.ts.astro.it/castelli/colors.html.
Upon request we can also provide models transferred to the Stroemgren Photometric Systems employing the colour - effective temperature relations by Clem, J.L., VandenBerg, D.A., Grundahl, F. & Bell, R.A. 2004, AJ, 127, 1227.
In order to accurately sampling the morphology of the evolutionary tracks we have adopted 16 key stages along the evolutionary track, more in detail:
Low-mass stars denotes in this case all objects which do not develop a convective core during the whole central H-burning phase; the high-mass structures are all the others.
For those structures which do not present the Bump along the RGB, we have - arbitrarily - chosen as representative of the key points 6 and 7, two points whose brightness was intermediate between the luminosities corresponding to the key points 5 and 8.
The correspondence between key stages and rows is the following:
For more details about these choices, please contact one of the authors.
In case one is interested in the complete evolutionary track (i.e, a non normalized track) as well as to more information about the models (such as details on the convective zones, energy produced by the various nuclear burnings, internal structure and so on) we will be pleased to provide them upon request. All comments/suggestions/requests are welcome. We hope that this database will be useful to your work!
Our best regards!!!
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