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VI/40       Revised Yale Isochrones and Luminosity Functions (Green+ 1987)

The Revised Yale Isochrones and Luminosity Functions Green E.M., Demarque P., and King C.R. <Yale University Observatory, New Haven, Connecticut (1987)>
ADC_Keywords: Models, evolutionary ; Isochrones ; Stars, ages Description: The revised isochrones and luminosity functions (LFs) are based on the stellar evolution calculations of Mengel et al. (1979) and Sweigart and Gross (1978). The revised tables comprise the most complete (as of 1987) isochrone grid available in both age and composition. The improvement in the revised catalog is the inclusion of UBVRI data as well as the theoretical quantities, which are empirically matched to a wide range of observational UBVRI data (Green et al. 1987, unpublished). These tables enable users to interpolate between isochrones, to plot isochrones in order to fit color-magnitude diagrams, luminosity functions to compare with observational data, and to construct stellar population models. To facilitate the use of isochrones, we (at the Astronomical Data Center, in 1987) had made available several FORTRAN programs, ISOTRP, LF, and subroutines. They incorporate our experience of the best methods of interpolation, minimization of precision problems, and how to deal with compositions and ages that are not always complete. ISOTRP allows the user to interpolate for any helium abundance or metallicity in the range of the Revised Yale Isochrone tables. LF constructs customized differential luminosity functions for Mbol or a UBVRI magnitude, for any bin size, and for any initial mass functions. In addition to the 24 isochrone files and the FORTRAN programs, we (at ADC) have included the color table that was used to convert from [Fe/H], log Teff, and log g to BC, U-B, B-V, V-R, R-I, in the isochrone data files. The data cover a complete grid with [Fe/H] from 1.00 to -3.5 in steps of 0.50, Teff from 2800 to 20000 K, and log g from 0.00 to 6.00. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file header.dat 23 644 The isochrone header file isoc5.112 125 2374 The isochrones for Z=1E-1 and Y=0.20 isoc5.113 125 2457 The isochrones for Z=1E-1 and Y=0.30 isoc5.121 125 3100 The isochrones for Z=1E-2 and Y=0.10 isoc5.122 125 4673 The isochrones for Z=1E-2 and Y=0.20 isoc5.123 125 4440 The isochrones for Z=1E-2 and Y=0.30 isoc5.124 125 3963 The isochrones for Z=1E-2 and Y=0.40 isoc5.131 125 2466 The isochrones for Z=1E-3 and Y=0.10 isoc5.132 125 3956 The isochrones for Z=1E-3 and Y=0.20 isoc5.133 125 3957 The isochrones for Z=1E-3 and Y=0.30 isoc5.134 125 2318 The isochrones for Z=1E-3 and Y=0.40 isoc5.141 125 2416 The isochrones for Z=1E-4 and Y=0.10 isoc5.142 125 4208 The isochrones for Z=1E-4 and Y=0.20 isoc5.143 125 4034 The isochrones for Z=1E-4 and Y=0.30 isoc5.144 125 2216 The isochrones for Z=1E-4 and Y=0.40 isoc5.151 125 2457 The isochrones for Z=1E-5 and Y=0.10 isoc5.152 125 3461 The isochrones for Z=1E-5 and Y=0.20 isoc5.153 125 4037 The isochrones for Z=1E-5 and Y=0.30 isoc5.154 125 2207 The isochrones for Z=1E-5 and Y=0.40 isoc5.422 125 4117 The isochrones for Z=4E-2 and Y=0.20 isoc5.423 125 4464 The isochrones for Z=4E-2 and Y=0.30 isoc5.432 125 4224 The isochrones for Z=4E-3 and Y=0.20 isoc5.433 125 3343 The isochrones for Z=4E-3 and Y=0.30 isoc5.442 125 4238 The isochrones for Z=4E-4 and Y=0.20 isoc5.443 125 3837 The isochrones for Z=4E-4 and Y=0.30 colortbl.dat 53 3510 Color Table (2) isotrp.for 74 436 Program to interpolate isochrones (1) lf.for 72 473 Program to calculate luminosity functions (1) lsq.for 72 284 Least Squares subroutine (1) parrot.for 80 262 Interpolation subroutine (1) suave.for 80 68 Smoothing subroutine (1) upcase.for 80 20 Conversion to upper-case subroutine (1)
Note (1): These programs are written in VAX/VMS FORTRAN, and were slightly modified at CDS to accommodate f77 compilers on Sun workstations. See below the notes on the programs ISOTRP and LF. Note (2): This color table is not called by the provided programs: ISOTRP or LF. It was used originally to derive the observational quantities in the 24 data files, and is included for reference only. The basic description of the color calibration for the isochrones is in "Calibration of Stellar Ages", ed. A. G. Davis Philip, p.81 (1988). The data cover a complete grid with [Fe/H] from 1.00 to -3.5 in steps of 0.50, Teff from 2800 K to 20000 K, and log g from 0.00 to 6.00. Note the first two records which were the filename and labels of individual data field were removed.
Byte-by-byte Description of file: colortbl.dat
Bytes Format Units Label Explanations
1- 5 F5.2 Sun [Fe/H] The abundance ratio of Fe and H 7- 12 F6.0 K Teff Gas effective temperature 15- 18 F4.2 cm/s2 log(g) Log of gravity 19- 25 F7.3 mag BC Bolometric Corrections 26- 32 F7.3 mag U-B Photoelectric U-B colors 33- 39 F7.3 mag B-V Photoelectric B-V colors 40- 46 F7.3 mag V-R Photoelectric V-R colors 47- 53 F7.3 mag R-I Photoelectric R-I colors
Isochrone data: Each isochrone is preceded with a header line: IGB,Npts,Alpha Format (I3,8X,I3,F5.2) followed by Npts lines providing the quantities described in the Byte-by-byte Description of files isoc5.* The information in the header.dat file summarizes the file specific information taken from the data files isoc5.* Each isochrone file contains isochrones for a single composition. The first 2 numbers of the file extension indicate Z, and the third number indicates Y for that file. For example isoc5.123 contains data for Z=1x10^(-2), Y=0.30; isoc5.432 pertains to Z=4x10-3, Y=0.20, etc. Zsun has been defined to be 0.02. Each isochrone file has a Zero Age Main Sequence (ZAMS) plus as many of the following ages as could be interpolated (or reasonably extrapolated) from the Mengel et al. (1979) and Sweigart and Gross (1978) mass tracks (units are 10 yrs): 150, 200, 350, 500, 750, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000, 10000, 11000, 12000, 13000, 14000, 15000, 16000, 17000, 18000, 20000, 22000, 25000. The data files include the following compositions and ages: ------------------------------------------------------------ Z Y MS-turnoff ages Age range with Giant-Branches ------------------------------------------------------------ 0.00001 0.10 0, 200 - 25000 none 0.20 0, 200 - 25000 11000 - 25000 0.30 0, 150 - 25000 6000 - 25000 0.40 0, 150 - 18000 none ------------------------------------------------------------ 0.0001 0.10 0, 200 - 25000 none 0.20 0, 200 - 25000 3000 - 25000 0.30 0, 150 - 25000 6000 - 25000 0.40 0, 200 - 18000 none ------------------------------------------------------------ 0.0004 0.20 0, 200 - 25000 3000 - 25000 0.30 0, 150 - 25000 6000 - 20000 ------------------------------------------------------------ 0.001 0.10 0, 200 - 25000 none 0.20 0, 200 - 25000 6000 - 25000 0.30 0, 150 - 25000 7000 - 25000 0.40 0, 150 - 18000 none ------------------------------------------------------------ 0.004 0.20 0, 200 - 25000 3000 - 22000 0.30 0, 150 - 17000 6000 - 17000 ------------------------------------------------------------ 0.01 0.10 0, 200 - 25000 15000 - 25000 0.20 0, 150 - 2500 750 - 25000 0.30 0, 150 - 20000 500 - 20000 0.40 0, 150 - 20000 3000 - 20000 ------------------------------------------------------------ 0.04 0.20 0, 150 - 22000 3000 - 22000 0.30 0, 150 - 25000 1500 - 25000 ------------------------------------------------------------ 0.1 0.20 0, 150 - 22000 none 0.30 0, 150 - 25000 none ------------------------------------------------------------ Byte-by-byte Description of file: header.dat
Bytes Format Units Label Explanations
1- 9 A9 --- Name Isochrone filename 11- 13 I3 --- IGB *Evolutionary status 15- 17 I3 --- Npts Number of points for this isochrone 19- 23 F5.2 --- Alpha *[1.50] Mixing length to scale height ratio
Note on IGB: 0 indicates Main Sequence (MS) turnoff only -1 means Red Giant branch (RGB) included Note on Alpha: Effective convective mixing length to pressure scale height ratio, always 1.50.
Byte-by-byte Description of file: isoc5.*
Bytes Format Units Label Explanations
1- 3 I3 --- EEP Equivalent evolutionary point number 4 A1 --- Mflag *[* ] Mass data flag 5- 10 I6 Myr AGE The age in units of 10^6 yrs 11- 12 I2 % Y Helium abundance 13- 16 I4 10-5 Z *Metal abundance 17- 25 F9.6 solMass Mass Mass 26- 35 F10.7 K Teff Effective temperature 36- 45 F10.7 solLum Lumin Luminosity 46- 60 E15.9 --- DN1 *Initial mass function 1 61- 75 E15.9 --- DN2 *Initial mass function 2 76- 90 E15.9 --- DN3 *Initial mass function 3 91- 97 F7.3 mag V *Visual magnitude 98-104 F7.3 mag U-B *Photoelectric U-B colors 105-111 F7.3 mag B-V *Photoelectric B-V colors 112-118 F7.3 mag V-R *Photoelectric V-R colors 119-125 F7.3 mag R-I *Photoelectric R-I colors
Note on Mflag: "*" if the mass point was extrapolated or it was interpolated over a very large interval. Note on Z: Metal abundance. The only exceptions are that Z = 0000 then Z is 1 and if Z = 9999 then Z is 10000 (in units of 1E-5) Note on DN1, DN2, DN3: The number of stars between J and J+1, for three different MS initial mass functions, s=1+x=0, 2.35, and 4.00, where dN(m) ≃ m^(-s). The constant s was chosen to normalize all dN to 1000 stars in the range 0.5 < m < 1.0 solar masses on the initial MS. Note on V, U-B, B-V, V-R, R-I: UBVRI magnitude and colors; Johnson UBV and Cousins RI.
The FORTRAN program ISOTRP: ISOTRP interpolates for requested values of Y and Z in the isoc5.xxx files, for the tabulated ages. It also allows the user to specify the values to be used for S, the initial mass function (IMF) exponent. Interpolation for the resulting mass, log Teff, log L, (dN(M),M=1,3), V, U-B, B-V, V-R, and R-I is done point by point between the equivalent evolutionary points in each isochrone file. All user-specified quantities are requested interactively when the program is run. The inputs are always prompted by a question mark, and are read in free format. The output file, iso.out, has the same format as the original isoc5.xxx files, except that the new header line also lists the values of S used to calculate the numbers of stars. Interpolation is done linearly in Y. Linear interpolation in log Z is used if only two of the input isochrones contain the age in question; otherwise the interpolation is non-linear in log Z. The non-linear interpolation uses at most the two isochrones on either side of the input Z value, so that it is never necessary to enter input isochrone files for more than 4 metallicities. If interpolation is done in Y as well as Z, both sets of input Y isochrone files must be for exactly the same group of Z values. It is useful to check the table of "compositions and ages" for the files and ages to be interpolated. For example, if there are 4 input Z files but only 2 of the input files have RGB's for a given age, the metallicity interpolation will change from non-linear to linear at the base of the RGB. In general, this will cause a glitch in log Teffs log L, and mass at that point (EEP 111). ISOTRP can be used with a single input isochrone to simply change the values of S, without any interpolation in Y or Z. The isochrones for Z=0.10 are the most suspect, due to uncertainties in the opacity tables and the theoretical-to-observational transformations; use Z = 0.10 for interpolation only when absolutely necessary. (N.B. ISOTRP expects the input files to be the original isoc5.xxx files, in that the input Y's must be multiples of 0.10 and the first dN column must be calculated for s=0.0). ISOTRP example: $ RUN ISOTRP ISOCHRONE INTERPOLATION PROGRAM INTERPOLATES IN Y AND Z, FOR AGES TABULATED IN INPUT DATA FILES, WITH THREE MS IN1TIAL MASS FUNCTIONS Helium abundance ? .24 Metal abundance ? .02 IMF exponents (defaults are S(1)=0.0, S(2)=2.35, and S(3)=4.0) S(1) ? <CR> S(2)? 1. S(3) ? 2.35 List ages in ascending order (units of 10**6 yrs, <CR> to end) OR Enter "ALL" to do all ages in input files ? 5000 ? <CR> Input isochrone files for Y = 0.20 (one per line, in order of increasing Z, <CR> to end) ? ISO.132 ? ISO.432 ? ISO.122 ? ISO.422 ? <CR> Input isochrone files for Y = 0.30 ? ISO.133 ? ISO.433 ? ISO.123 ? ISO.423 ? <CR> WARNING: INTERPOLATION CHANGED FROM NONLINEAR TO LINEAR ON RGB FOR 5000 Interpolation completed $ TYPE ISO.OUT (some columns have been edited out to fit on this page) -1 182 1.50 0.00 1.00 22* 5000242000 0.681842 3.6380655-0.8724267 (...) 7.680 1.081 (...) 23* 5000242000 0.733311 3.6770521-0.7122780 (...) 6.985 0.801 (...) 24* 5000242000 0.777090 3.7014384-0.5826680 (...) 6.544 0.621 (...) 25 5000242000 0.813713 3.7167270-0.4773737 (...) 6.218 0.507 (...) 26 5000242000 0.844470 3.7257763-0.3908702 (...) 5.964 0.436 (...) 27 5000242000 0.870474 3.7321016-0.3183704 (...) 5.758 0.388 (...) 28 5000242000 0.892720 3.7375008-0.2564802 (...) 5.583 0.349 (...) (...) The FORTRAN program LF: LF reads isochrone data from an existing iso.out file, original or interpolated, and calculates a differential luminosity function for the user's choice of: a) either Mbol, U, B, V, R, or I magnitude, b) one of the three input IMF exponents in the input file, c) all or a subset of the ages in the input file, d) the magnitude bin size for the LF, e) the starting magnitude (faint boundary). (You may copy any of the original isoc5.xxx files to iso.out if ISOTRP was not used, since all the files have the same format.) The recommended magnitude bin size is between 0.02 and 1.0 mag (less than 0.02 overflows arrays and exceeds the accuracy of the isochrones). Obviously, the choice of bin size may affect the visibility of various features in the LF. The user may specify a value for the faint boundary of the LF, or alternatively, have the program choose LF boundaries relative to the bluest point on each isochrone. If the requested starting magnitude for the LF corresponds to a point fainter than either Mbol = 8.0 or the first Mbol in the isochrone file, the program will start the LF calculation at a brighter interval than requested. The LF program also asks the user to choose log Teff or some UBVRI color (e.g. B-V, B-R, V-I, etc.), and calculates the effective log Teff or color for each magnitude bin, properly weighted by the numbers of stars at each temperature. LF's may be calculated for ALL the ages in the input file, or for a STD subset (500, 1000,2000,4000,6000,9000,12000,16000,20000), or for any set of specific ages (contained in the file) that the user selects. The resulting LF is printed in a file called lf.out. The number of stars tabulated, and the effective log Teff or color, refer to the interval between that magnitude and the next brighter magnitude. The normalization is the same as above, to 1000 stars between 0.5 and 1.0 solar masses on the initial MS. An entry is marked with an * if any part of the interval was extrapolated in the calculation of the input isochrone. If an isochrone decreases in brightness over more than one magnitude bin between the turnoff and the base of the RGB, partial LF's are listed in addition to the total LF: 1) MS, 2) SGB, and 3) RGB, if it exists. N.B. ISOTRP and LF evolved on the Mt. Stromlo VAX, and it may be necessary for users on other computers to modify some of the coding to work on their machines. Examples and sample outputs for both have been included at the end of these notes, to check the proper operation of the programs in case such modifications are required. Because the number of significant digits stored in other computers may differ, the LF numbers may be different at the 3rd or 4th decimal place. LF example: $ RUN LF enter input isochrone file >iso.out output LF file >lf.out DIFFERENTIAL LUMINOSITY FUNCTION PROGRAM Y = 0.24 Z = 0.02 Select value of S = MS IMF exponent to be used for LF (1 for S=0.00, 2 for S=1.00, 3 for S=2.35) ? 3 Select a magnitude (BOL, U, B, V, R, or I) ? bol Select Log Teff or any UBVRI color (B-V, V-I, B-R, U-I, etc) ? log Teff Enter LF bin size (mag) ? .025 Enter faintest BOL magnitude OR Enter "BLUE" to choose bin boundaries relative to bluest pt on isochrones ? 6. $TYPE LF.OUT Y = 0.24 Z = 0.02 S = 2.35 AGE = 5000 Total Log Mbol dN Teff MS SG RG 6.000 * 4.984614 3.7165 4.98461 3.716 5.975 4.948221 3.7176 4.94822 3.718 5.950 4.911634 3.7186 4.91163 3.719 5.925 4.873771 3.7197 4.87377 3.720 5.900 4.834680 3.7207 4.83468 3.721 etc Acknowledgements: The original introductory text of "The Revised Yale Isochrones and Luminosity Functions" by Green et al. (1987) and its attached letter of Wayne H. Warren were used to create this ReadMe file. The author provided the color calibration reference. References: Ciardullo, R.B., and Demarque, P. 1978, Trans. Yale. Obs., vols 33-35. Davis Philip, A.G., ed. (1988). Calibration of Stellar Ages, p. 81 Kurucz, R.L. 1979, Ap J. Suppl., 40, 1 Mengel, J.G., Sweigart, A.V., Demarque, P., and Gross, P.G. 1979, Ap J. Suppl., 40, 733 (1979ApJS...40..733M) Sweigart, A.V., and Gross, P.G. 1978, Ap J. Suppl., 36, 405. (1978ApJS...36..405S) VandenBerg, D.A., and Bell, R.A. 1985, Ap.J. Suppl., 58, 561. (1985ApJS...58..561V); see also catalog VI/55
(End) C.-H. Joseph Lyu; Paul Kuin [Hughes STX/NASA] 12-Jul-1996
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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