Gas-Phase Metallicity Gradients at z~2


The broad spectral coverage and high angular resolution of GLASS are ideal for detailed studies of galaxies at intermediate redshifts. In Jones et al. 2015 our team analyzed the spatially resolved stellar mass and gas-phase metallicity in a system of three strongly lensed galaxies at redshift z=1.855, drawn from the first complete GLASS data set (MACS0717).

These initial GLASS data reveal strong, spatially extended emission lines in all three galaxies. We find no significant radial variation in metallicity, possibly as a result of gravitational interaction among the galaxies.

These results represent the first constraint of metallicity gradient evolution using HST. Our analysis also extends previous studies of the mass-metallicity relation to an order of magnitude lower stellar mass, confirming that GLASS is able to characterize dwarf galaxies at intermediate redshift. The mass-metallicity relation and metallicity gradient evolution are both valuable diagnostics of how gas cycles in and out of galaxies over cosmic time.

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