0 Assigned ID: 399 ----- Attempting Submission 1 (Fri Mar 06 04:56:52 GMT 2020) ----- A major part of the HST ULLYSES observing program consists of an ambitious initiative to record medium-resolution UV spectra of a large number of hot stars in the Large and Small Magellanic Clouds. The data that will emerge from this comprehensive survey will enable us to measure gas-phase abundances for a broad range of different elements for these two nearby galactic systems with low metallicities and, at the same time, define the character of extinction as a function of wavelength arising from dust in both the Milky Way and Magellanic Cloud systems. Our objective is to determine the composition of this dust after we understand how rapidly the elements are depleted from the gas phase as they condense into solid form. While useful on its own, this information will also be of value to investigations of abundances in distant Damped Lyman Alpha systems, where observed atomic column densities must have upward corrections to compensate for the depletions in order to arrive at true total abundances. Dr. Jenkins has had well over 4 decades of experience in working with UV spectroscopic data gathered from Copernicus, IUE, FUSE, IMAPS, and HST. His principal interest is in studies of the composition and physical state of the interstellar and intergalactic medium. His landmark paper published in 2009 formed the basis of unifying the trends in gas-phase element depletions in the Milky Way ISM, and this paper forms the basis of the research program proposed here, which is now applied to the Magellanic Clouds. He has also published a paper on the abundances of elements and depletion trends for the ISM inside the Small Magellanic Cloud, based on HST observations (program ID = 13778) Dr. Roman-Duval has headed a major HST observing program (ID = 14675) to measure ISM abundances in the Large Magellanic Cloud and another effort to observe stars in a very low metallicity galaxy (ID = .15880). She has assumed a leadership role in formulating the ULLYSES program. Dr. Welty has had considerable achievements in research on the composition and physical properties of the ISM. He has been the lead author on recent papers that reported observations of Ti II, C2 and C3, HI and H2, and C I fine-structure excitations in the Magellanic Clouds. He is also a participant in the group that planned the ULLYSES observations. Drs. Fitzpatrick, Massa, and Gordon have a long history of performing research on the behavior of extinction curves, dating all the way back to the days of IUE. Over the last decade, all three have collaborated on writing papers on extinction. Stellar Populations and the Interstellar Medium 0 Legacy false false true false false SUPPORTED