Local Starbursts in a Cosmological Context

Abstract

In this contribution I introduce some of the major issues that motivate the conference, with an emphasis on how starbursts fit into the “big picture”. I begin by defining starbursts in several different ways, and discuss the merits and limitations of these definitions. I will argue that the most physically useful definition of a starburst is its “intensity” (star-formation rate per unit area). This is the most natural parameter to compare local starbursts with physically similar galaxies at high redshifts, and indeed I will argue that local starbursts are unique laboratories to study the processes at work in the early Universe. I will describe how NASA's GALEX mission has uncovered a rare population of close analogs to Lyman Break Galaxies in the local Universe. I will then compare local starbursts to the Lyman Break and sub-mm galaxies' high-redshift populations, and speculate that the multi-dimensional “manifold” of starbursts near and far can be understood largely in terms of the Schmidt/Kennicutt law and galaxy mass-metallicity relation. I will briefly summarize the properties of starburst-driven galactic superwinds and their possible implications for the evolution of galaxies and the intergalactic medium. These complex multiphase flows are best studied in nearby starbursts, where we can study the hot X-ray gas that contains the bulk of the energy as well as newly produced metals.