The MOSDEF Survey: Probing Resolved Stellar Populations at z~2 using a New Bayesian-defined Morphology Metric

Studying the resolved structure of high-redshift galaxies can give insight into the evolution of global galactic properties. For example, understanding the distribution of dust and how it affects the scattering and attenuation of starlight is important for accurately recovering intrinsic star-formation rates. We investigate how the distribution of dust changes as galaxies increase in stellar mass at z~2, when star-formation activity was at its highest and stellar mass assembly was rapidly proceeding. To completely characterize the galaxies, we pair high-resolution, multi-waveband CANDELS/3D-HST imaging with H-alpha and H-beta emission line observations from the MOSFIRE Deep Evolution Field (MOSDEF) survey and construct stellar population and dust maps of ~300 star-forming galaxies at spectroscopic redshifts 1.36 < z < 2.66. We quantify resolved stellar continuum color excess distributions by using the Gini and M20 coefficients alongside a newly defined parameter, "patchiness" (P). We find that high-mass galaxies exhibit patchier stellar continuum color excess distributions with lower Gini coefficients compared to low-mass galaxies. Our results support a picture where dust is smoothly distributed in low-mass galaxies, suggesting efficient mixing of dust throughout their ISM. On the other hand, the dust distribution is patchier in high-mass galaxies, such that dust is concentrated near regions of active star-formation and dust mixing timescales are expected to be longer