The results of our Hubble Cosmic Origins Spectrograph SNAP program, which has had data trickling in since late 2013, are now in press with ApJ! The paper was authored by Erika Zetterlund, a second-year at CU and the first grad student member of my research group, along with Claus Leitherer and Charles Danforth, and shows some very exciting results on developing and testing interstellar medium diagnostics in the UV.

We see great agreement between our COS spectra and the predictions of stellar population synthesis models from Starburst99 (left), and a very strong linear relationship between the UV and optical metallicity diagnostics! Right now we have no good means of comparing metallicities determined from different wavelength regimes; this is a really exciting sign that with more data and models we’ll be able do this very easily, unifying huge samples of star-forming galaxies observed across a broad range of redshifts. Finally, we compiled some great observational results and theoretical predictions for the short-wavelength UV slope, which is a good diagnostic for extinction particularly at high redshifts.

The paper will be published in ApJ and can now be downloaded from astro-ph.