Testing the Universality of the Fundamental Metallicity Relation at High Redshift Using Low-Mass Gravitationally Lensed Galaxies

Understand

We present rest-frame optical spectra for a sample of 9 low-mass star-forming galaxies in the redshift range 1.5 < z < 3 which are gravitationally lensed by foreground clusters.

• We used Triplespec, an echelle spectrograph at the Palomar 200-inch telescope that is very effective for this purpose as it samples the entire near-infrared spectrum simultaneously.
• By measuring the flux of nebular emission lines we derive gas phase metallicities and star formation rates, and by fitting the optical to infrared spectral energy distributions we obtain stellar masses.
• Taking advantage of the high magnification due to strong lensing we are able to probe the physical properties of galaxies with stellar masses in the range 7.8 < log M/Msun < 9.4 whose star formation rates are similar to those of typical star-forming galaxies in the local universe.