Exploring the high-redshift Universe
Insights from Local Analogues to z~5 Lyman Break Galaxies
Stephanie Greis
University of Warwick
Studying high-redshift star-forming systems, such as Lyman Break Galaxies (or LBGs), allows us to learn more about the early stages of galaxy evolution, their impact on processes such as cosmic reionization, and ultimately the origin of the Milky Way. However, the study of such distant sources is complicated by their small apparent sizes and faintness.
To improve their interpretation, we recently established a sample of 180 faint local galaxies, selected to match the z~5 LBGs' UV colours and luminosity density (and thus star-formation rate density). Using SED fitting from UV to FIR, as well as spectroscopic methods, we determine their dust content, stellar population ages, metallicities, star formation rates, and masses.
We find that the objects in our sample are young (~60 - 400 Myr), moderately massive (log(M*)~9-10) star-forming systems with low dust extinction (E(B-V)~0.1) and ~0.5 Solar metallicity. Using a range of diagnostics, we confirm that the objects in our sample are star formation driven, and (most likely) do not contain AGN. Given these results, we establish that a large fraction of our sample can be used as local analogues to z~5 LBGs, making them a more appropriate comparison sample for the most distant galaxies than those previously investigated. In this presentation, we will present the recent published results of our programme of follow-up and analysis, their implications for z~5 LBGs, as well as how future studies of these local analogues will enable us to shed light on some of the first galaxies which formed in the Universe.


13:30 - 15:00
EX - LT2 (200)