------------------------------------------------------------------------------- ************************************** CaTffs, version 1.0 (19-December-2001) ************************************** INDEX 1 - PROGRAM DESCRIPTION 1.1 - Introduction 1.2 - Error estimation 2 - INSTALLATION 3 - PROGRAM USE 3.1 - Description 3.2 - Examples 4 - REFERENCES ------------------------------------------------------------------------------- 1 - PROGRAM DESCRIPTION ======================= 1.1 - Introduction ------------------ This program predicts the strength of the new Ca triplet indices (CaT*, PaT and CaT) defined in Cenarro et al. (2001; Paper I) on the basis of the empirical fitting functions computed in Cenarro et al. (2002; Paper III). It performs the required interpolations between the different local functions as explained in Paper III. Therefore, it is a very simple program specially designed to be easily implemented into stellar populations synthesis codes. This software is copyright by J. Gorgas, A. J. Cenarro and N. Cardiel. 1.2 - Error estimation ---------------------- Together with the indices predictions, the program also computes the random errors associated to such predictions resulting from the covariance matrices of the fits (for the indices CaT* and PaT). This ensures a reliable error index estimation for any combination of input atmospheric parameters. See more details on errors estimation in Paper III. 2 - INSTALLATION ================ You only need the adequate FORTRAN compiler for your OS. Install the program by executing: % g77 -o output_name CaTffs.f (Linux) % f77 -o output_name CaTffs.f (Alpha, Sparc) NOTE: Although we provide a complet program on its own, obviously, the main program can be deleted and the subroutine "predicted()" (and their associated subroutines) can be included in any separate code. 3 - PROGRAM USE =============== 3.1 - Description ----------------- When you execute the program, you get the following message: "Input Teff, log(g), [Fe/H]" You just have to type the three atmospheric parameters - effective temperature, in K - logarithm (base 10) of the surface gravity, in dex - metallicity, in dex all of them in the same line and between comas. It returns the INDICES CaT*, PaT and CaT (first column, in angstroms), the corresponding ERRORS (second column, in angstroms) and an integer CODE indicating the success and reliability of the prediction (third column). Notes: - Output CODES: 0 -> OK 1 -> Extrapolation to high temperatures 2 -> Extrapolation to low temperatures 3 -> Extrapolation in log(g) (uncertain value) -1 -> Error (no Teff) -2 -> Error ([Fe/H] needed) -3 -> Error (log(g) needed) -5 -> Error - A value higher or equal to 99. in input log(g) or [Fe/H] is sometimes accepted (it means that this parameter is unknown). For some parameter ranges, in which the fitting functions do not depend on gravity and/or metallicity, an index value can still be computed (see Paper III). 3.2 - Examples -------------- INPUT --> 4550.,2.30,-0.70 OUTPUT --> CaT* = 6.677 0.132 0 PaT = 0.638 0.036 0 CaT = 7.270 0.137 In this case, the codes "0" are indicating that the predicted indices are OK. INPUT --> 5000.,5.20,0.00 OUTPUT --> CaT* = 6.368 0.439 3 PaT = 0.594 0.095 3 CaT = 6.920 0.448 The codes "3" indicate that, for this region of the parameter space, the gravity is out of the library coverage. Note that this could not be the case for other parameters regions as in the next example. INPUT --> 3500.,5.20,0.00 OUTPUT --> CaT* = 4.826 0.131 0 PaT = 0.277 0.101 0 CaT = 5.084 0.161 4 - REFERENCES ============== - Cenarro A.J., Cardiel N., Gorgas J., Peletier R.F., Vazdekis A., Prada F., 2001, MNRAS, 326, 959 (Paper I) - Cenarro A.J., Gorgas J., Cardiel N., Vazdekis A., Peletier R.F., 2002, MNRAS, 329, 863 (Paper III)