3:30–4:30 pm ERC 161
Claudia Scarlata (University of Minnesota) "Observational constraints on the gas reservoir of the smallest galaxies"
The gas reservoir around galaxies plays a fundamental, while still poorly understood, role in regulating the growth of galaxies, in establishing the scaling relation we observe among galaxies' physical properties as well as in modulating the escape of ionizing radiation from galaxies, and thus their contribution to the reionization process. Particularly at the low mass end of the mass function, where most of the galaxies reside, the interplay between energy feedback and gas accretion is difficult to model and hard to pin-down observationally. In this talk I will present new results on Pox186, an exceptionally small dwarf starburst galaxy hosting a stellar mass of ¡10^5 Ms. This galaxy shows all characteristics typical of a Lyman continuum emitter, and it is a likely analog of low-mass reionization-era galaxies. I will discuss spatially resolved kinematic data which show evidence of an ionized outflow, with a small mass-loading factor, inconsistent with extrapolations from numerical simulations to similar masses. I will present new results based on modeling of rest-frame far-UV spectra which independently constraints the extent and column density of the gas, and suggest that over the course of its history, Pox186 has lost a large fraction of the carbon produced by the stars.
