Abstract.A new set of evolutionary synthesis spectra are presented for Simple Stellar Populations (SSPs) covering ranges in metallicity from 0.02 ≤ Z/Z ≤ 2.5 and ages from 4 × 10 6 yr ≤ t ≤ 16 Gyr. They are based on the most recent isochrones from the Padova group that extend earlier models by the inclusion of the thermal pulsing AGB phase for stars in the mass range 2 M ≤ m ≤ 7 M in accordance with the fuel consumption theorem. We show that with respect to earlier models, inclusion of the TP-AGB phase leads to significant changes in the (V − I) and (V − K) colors of SSPs in the age range from 10 8 to ∼ > 10 9 yr. Using model atmosphere spectra from Lejeune et al. (1997Lejeune et al. ( , 1998, we calculate the spectral evolution of single burst populations of various metallicities covering the wavelength range from 90 Å through 160 µm. Isochrone spectra are convolved with filter response functions to describe the time evolution of luminosities and colors in Johnson, Thuan & Gunn, Koo, HST, Washington and Strömgren filters. The models and their results are not only intended for use in the interpretation of star clusters but also for combination with any kind of dynamical galaxy formation and/or evolution model that contains a star formation criterion. Moreover, the evolution of these single burst single metallicity stellar populations is readily folded with any kind of star formation -and eventually chemical enrichment -history to describe the evolutionary spectral synthesis of composite stellar populations like galaxies of any type with continuous or discontinuous star formation. For these latter purposes we also present the time evolution of ejection rates for gas and metals for two different Initial Mass Functions (IMFs) as well as cosmological and evolutionary corrections for all the filters as a function of redshift for 0 ≤ z ≤ 5 and two different cosmologies. Extensive data files are provided in the electronic version, at CDS, and at our above www-address.

Abstract. The composite stellar populations of galaxies comprise stars of a wide range of metallicities. Subsolar metallicities become increasingly important, both in the local universe when going from early towards later galaxy types as well as for dwarf galaxies and for all types of galaxies towards higher redshifts. We present a new generation of chemically consistent evolutionary synthesis models for galaxies of various spectral types from E through Sd. The models follow the chemical enrichment of the ISM and take into account the increasing initial metallicity of successive stellar generations using recently published metallicity dependent stellar evolutionary isochrones, spectra and yields. Our first set of closed-box 1-zone models does not include any spatial resolution or dynamics. For a Salpeter initial mass function (IMF) the star formation rate (SFR) and its time evolution are shown to successfully parameterise spectral galaxy types E, ..., Sd. We show how the stellar metallicity distribution in various galaxy types build up with time to yield after ∼12 Gyr agreement with stellar metallicity distributions observed in our and other local galaxies. The models give integrated galaxy spectra over a wide wavelength range (90.9 Å-160 µm), which for ages of ∼12 Gyr are in good agreement not only with observed broad band colours but also with template spectra for the respective galaxy types. Using filter functions for Johnson-Cousins U, B, V, R C , I C , as well as for HST broad band filters in the optical and Bessel & Brett's NIR J, H, K filter system, we calculate the luminosity and colour evolution of model galaxies over a Hubble time. Including a standard cosmological model (H 0 = 65, Ω 0 = 0.1) and the attenuation by intergalactic hydrogen we present evolutionary and cosmological corrections as well as apparent luminosities in various filters over the redshift range from z ∼ 5 to the present for our galaxy types and compare to earlier models using single (=solar) metallicity input physics only. We also resent a first comparison of our cc models to HDF data. A more detailed comparison with Hubble Deep Field (HDF) and other deep field data and an analysis and interpretation of high redshift galaxies in terms of ages, metallicities, star formation histories and, galaxy types will be the subject of a forthcoming paper.

Abstract.As a tool to interpret nearby and high redshift galaxy data from optical to K-band we present our chemically consistent spectrophotometric evolutionary synthesis models. These models take into account the increasing initial metallicity of successive stellar generations using recently published metallicity dependent stellar evolutionary tracks, stellar yields and model atmosphere spectra.The influence of the metallicity is analysed. Dust absorption is included on the basis of gas content and abundance as it varies with time and galaxy type. We compare our models with IUE template spectra and are able to predict UV fluxes for different spectral types. Combined with a cosmological model we obtain evolutionary and k-corrections for various galaxy types and show the differences to models using only solar metallicity input physics as a function of redshift, wavelength band and galaxy type.

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Abstract. By consistently connecting the chemical and spectrophotometric evolution of galaxies we are able to include the effect of dust absorption. The time and redshift evolution of the extinction is based on the evolution of the gas content and metallicity. We present our evolutionary synthesis models which include dust absorption to analyze the UV emission in various galaxy types. We are able to predict the extinction E(B-V) for different galaxy types as a function of redshift. We further use these models to explore the range of metallicities in normal and starbursting galaxies and the metallicity distribution of the stellar population. Comparing our model spectral energy distributions (SEDs) with templates from R. C. Kennicutt's (1992, ApJS 79, 255) and A. L. Kinney et al.'s (1996, ApJ, 467, 38) atlas we show the detailed agreement with integrated spectra of galaxies and point out the importance of aperture effects. Combined with a cosmological model we show the differences in the evolutionary and K-corrections by comparing models with and without dust. DiscussionEli Dwek: A test of your models is their ability to explain (in addition to the extinction) the IR emission from the various types of galaxies. Have you done such calculations?Claudia Moller: I agree; this will be out next step. 413use, available at https://www.cambridge.org/core/terms. https://doi