Rest-Frame UV Spectra of Star-Forming Galaxies: From Z ∼ 3 to the Redshift Desert

Abstract

We present the results of detailed studies of the astrophysical conditions in z ∼ 3 Lyman Break Galaxies (LBGs), placing particular emphasis on what is learned from LBG rest frame UV spectra. By drawing from our database of ∼ 1000 spectra, and constructing higher S/N composite spectra from galaxies grouped according to various parameters, we can show how the rest-frame UV spectroscopic properties systematically depend on other galaxy properties. Such information is crucial to understanding the detailed nature of LBGs, and their impact on the surrounding IGM. We then turn to a new survey of UV-selected star-forming galaxies at z ∼ 1.5 – 2.5, in the so-called “redshift desert.” Adjusting the z ∼ 3 LBG color criteria to find similar types of galaxies at z ∼ 2, and using a UV-optimized spectroscopic set-up, we have assembled nearly 700 galaxies spectroscopically confirmed to lie in this virtually unexplored, yet critical, period in the history of the universe. Ongoing and future work will probe the detailed astrophysical conditions in z ∼ 2 galaxies.