Open Issues on the Synthesis of Evolved Stellar Populations at Ultraviolet Wavelengths

TL;DR

This paper reviews key issues in synthesizing evolved stellar populations at UV wavelengths, focusing on the FUV up-turn, age-metallicity degeneracy, and distant galaxy spectra, highlighting preliminary results and future prospects with new observatories.

Contribution

It provides a summary of recent investigations into UV synthesis issues and introduces a preliminary application of theoretical UV spectra to aged stellar populations.

Findings

Insights into the FUV up-turn in elliptical galaxies

Analysis of the age-metallicity degeneracy

Application of UV spectral grids to distant galaxy spectra

Abstract

In this paper we briefly review three topics that have motivated our (and others') investigations in recent years within the context of evolutionary population synthesis techniques. These are: The origin of the FUV up-turn in elliptical galaxies, the age-metallicity degeneracy, and the study of the mid-UV rest-frame spectra of distant red galaxies. We summarize some of our results and present a very preliminary application of a UV grid of theoretical spectra in the analysis of integrated properties of aged stellar populations. At the end, we concisely suggest how these topics can be tackled once the World Space Observatory enters into operation in the midst of this decade.