The Smith Cloud: A Source of Fuel for the Next Generation Stars

The Smith Cloud is a gas cloud that is rapidly approaching the Milky Way. By exploring how the Smith Cloud traverses the Galactic halo and through the surrounding ionizing radiation field, we can gain insight into galactic fountains processes. Using UV absorption-line spectra taken with the Cosmic Origin Spectrograph (COS) on the Hubble Space Telescope (HST) and HI 21-cm emission-line spectra taken with the Green Bank Telescope (GBT) along two QSO sightlines, we are exploring the physical properties of two small cloud fragments that have splintered off this high-velocity cloud. We Voigt profile fit both low- and high-ionization species, which we will use to estimate the ionization conditions and the relative ionization in the low and high ionization states. The Smith Cloud could supply our galaxy with more than 2 million solar masses of gas that the Milky Way could use to make the next generation of stars. By deciphering the processes that affect the Smith Cloud, we can better understand the gas cycle of our galaxy, as well as ones similar to ours.