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arXiv · 0910.4975

Resolved maps of stellar mass and SED of galaxies from optical/NIR imaging and SPS models

Stefano Zibetti·Stephane Charlot·Hans-Walter Rix
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Abstract

We report on the method developed by Zibetti, Charlot and Rix (2009) to construct resolved stellar mass maps of galaxies from optical and NIR imaging. Accurate pixel-by-pixel colour information (specifically g-i and i-H) is converted into stellar mass-to-light ratios with typical accuracy of 30%, based on median likelihoods derived from a Monte Carlo library of 50,000 stellar population synthesis models that include dust and updated TP-AGB phase prescriptions. Hence, surface mass densities are computed. In a pilot study, we analyze 9 galaxies spanning a broad range of morphologies. Among the main results, we find that: i) galaxies appear much smoother in stellar mass maps than at any optical or NIR wavelength; ii) total stellar mass estimates based on unresolved photometry are biased low with respect to the integral of resolved stellar mass maps, by up to 40%, due to dust obscured regions being under-represented in global colours; iii) within a galaxy, on local scales colours correlate with surface stellar mass density; iv) the slope and tightness of this correlation reflect/depend on the morphology of the galaxy.

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Stefano Zibetti, Stephane Charlot, Hans-Walter Rix. 2009-10-26. Resolved maps of stellar mass and SED of galaxies from optical/NIR imaging and SPS models. https://doi.org/10.1017/s1743921310002589

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