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Calibration Database System

THE BRUZUAL- CHARLOT ATLAS

BRUZUAL-CHARLOT ATLAS is a library of galaxy spectra computed by Bruzual and Charlot using their Isochrone Synthesis Spectral Evolutionary Code. The December 1995 version of the Bruzual-Charlot atlas consists of 21 instantaneous bursts characterized by different IMF slope functions, and mass limits. Each instantaneous burst contains 221 spectral energy distributions (SEDs) corresponding to 221 time steps from 0 to 20 Gyr.

To get to the original and complete Bruzual & Charlot library, i.e. set of binary data files and decoding programs, go to BRUZUAL-CHARLOT ATLAS. To learn all details about the content of this library and how to generate specific spectral templates, read first the postcript version of the README file you will find in the directory.

The on-line library of SEDs consists of 84 STSDAS binary files. All SEDs have been obtained using the original binary bc95*.ised files and the program galaxevpl as explained in the readme file of the Bruzual-Charlot library.

The on-line SEDs represent bursts characterized by a Salpeter initial mass function (IMF) with different ranges in lower and upper mass limits, and at several ages (10E5, 25E5, 50E5, 76E5, 10E6, 25E6, 50E6, 10E7, 50E7, 10E8, 50E8, 10E9 years) after the burst. SEDs for instantaneous and composite bursts are available. Each SED has 1187 wavelength points covering the 100 angstroms to 100 microns wavelength range, and the fluxes are given in units of solar luminosity per Angstrom. The nebular contribution to the spectral energy distribution, i.e. emission lines and nebular continuum, is not include in the SEDs.

A list of the on-line SEDs, and corresponding file names, is given in the table below. In the file name, the "XXXX" indicate the age of the burst. For example, the file bc95_d_50E5.tab contains the SED for a five million years old instantaneous burst characterized by a Salpeter IMF with lower and upper mass limits of 2.5 and 125 solar masses. Should ASCII files be preferred, please use the "tdump" task within the ttools package of IRAF to convert the STSDAS binary table format into an ASCII file.

     Table: Characteristics of the on-line Bruzual-Charlot SEDs

  File name       IMF    Lower Mass    Upper Mass       Notes 
                        (solar mass)  (solar mass)

bc95_a_XXXX   Salpeter      0.1           125       instantaneous
bc95_b_XXXX   Salpeter      0.1            65       instantaneous
bc95_c_XXXX   Salpeter      0.1            30       instantaneous
bc95_d_XXXX   Salpeter      2.5           125       instantaneous
bc95_e_XXXX   Salpeter      0.1           125       burst lasting 1Gyr
bc95_f_XXXX   Salpeter      0.1           125       exp. decreasing SFR with
                                                       e-folding time of 1Gyr
bc95_g_XXXX   Salpeter      0.1           125       constant SFR of
                                                       1E-10 M_solar/yr
 

To the CDBS-BC95 Atlas

To the BRUZUAL-CHARLOT Atlas.