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Better age estimations using UV-optical colours: breaking the age-metallicity degeneracy

S. Kaviraj·S. -C. Rey·R. M. Rich·Y. -W. Lee·S. -J. Yoon·S. K. Yi
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Abstract

We demonstrate that the combination of GALEX UV photometry in the FUV (~1530 angstroms) and NUV (~2310 angstroms) passbands with optical photometry in the standard U,B,V,R,I filters can efficiently break the age-metallicity degeneracy. We estimate well-constrained ages, metallicities and their associated errors for 42 GCs in M31, and show that the full set of FUV,NUV,U,B,V,R,I photometry produces age estimates that are ~90 percent more constrained and metallicity estimates that are ~60 percent more constrained than those produced by using optical filters alone. The quality of the age constraints is comparable or marginally better than those achieved using a large number of spectrscopic indices.

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S. Kaviraj, S. -C. Rey, R. M. Rich, Y. -W. Lee, S. -J. Yoon, S. K. Yi. 2007-11-02. Better age estimations using UV-optical colours: breaking the age-metallicity degeneracy. https://doi.org/10.1111/j.1745-3933.2007.00370.x

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