Jessica Werk

Title: Finding Galactic Metals in Unusual Places

Abstract: Young metal atoms, after they have been violently and suddenly ejected into the ambient ISM from their dead, massive birth stars, are faced with some options. Some may stay close to home, some may travel within their galaxies, some are taken in by newly forming stars along the way, and others perhaps even leave their galaxies. I have been investigating the fates of the metal atoms in galaxies by measuring gas-phase abundances in two largely uncharted regimes: the far outskirts of galactic disks and the circumgalactic medium (CGM).  In the first part of this talk, I will describe a search for outlying HII regions in the gaseous outskirts of extended, disturbed, and/or interacting gas-rich galaxies, and subsequent Gemini Telescope multi-slit spectroscopy from which I obtain the nebular oxygen abundances of numerous outlying and centrally-located HII regions. In the second part of this talk, I will describe ongoing work that aims to map and characterize the diffuse gas of the CGM around 67 galaxies using QSO absorption line spectroscopy with the new Cosmic Origins Spectrograph (COS) on HST.  Analyzing the metal content of both regimes offers some rather surprising clues about the overall fates of galactic metal atoms