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

Department of Physics, University of Oxford, Oxford, England, United Kingdom
Monthly Notices of the Royal Astronomical Society (Impact Factor: 5.23). 01/2006; 381(1). DOI: 10.1111/j.1745-3933.2007.00370.x
Source: arXiv

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. Comment: Published in MNRAS (2007), 381, L74 (doi: 10.1111/j.1745-3933.2007.00370.x)

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