SkyMapper Protected Science Project
Primordial Gaseous Seeds
Joss Bland-Hawthorn (U. Syd), Matthew Nichols (EPFL), Mary Putman (Columbia)
Dwarf galaxies represent some of the earliest formed structures and reflect the conditions of the early universe in which larger structures formed. Due to their proximity, most of the smallest dwarf galaxies known have been found in the vicinity of the Milky Way and Andromeda, where they have already been affected by the hot halo and potential of a larger galaxy. Unmolested versions of these dwarfs are likely to larger distances and still contain substantial quantities of gas which is fuelling ongoing star formation. We will use the main SkyMapper Survey to examine a population of HI clouds which show dwarf galaxy-like properties and could be host to these untouched galaxies which are potentially similar to the recently discovered dwarfs Leo P and Leo T that appear as faint smudges in SDSS. The southern sky provides many valuable targets for these systems with several surveys having found compact high velocity HI clouds that provide good dwarf galaxy candidates (Putman et al. 2002; Moss et al. 2013), and additional high resolution and sensitivity data will become available with ASKAP.
We will perform a systematic search in SkyMapper of the HI cloud candidates for resolved and unresolved stellar systems. Based on pre-existing techniques (e.g. Kniavez et al. 2004) we should easily detect HI seeds like Leo P at 2.3 Mpc and due to the nature of the search potentially detect Leo T like follow up candidates at 2.5 Mpc and Leo P like ones out to 6 Mpc.