Marla Geha

The Large Magellanic Cloud (LMC) is an irregular galaxy located 163,000 light-years away in the direction of constellation Dorado. It contains 10 billion stars and has a diameter of 14,000 light-years. A satellite of the Milky Way, the LMC is believed to have once been a barred spiral galaxy that was ripped apart by the Milky Way's gravity. (Instituto de Astrofisica de Canarias)

Many large galaxies are surrounded by systems of dwarf satellite galaxies. Geha is completing a census of the hundreds of tiny and faint galaxies that accompany several large nearby galaxies. To facilitate the work, she has been using multi-fiber spectroscopy on a 4-meter telescope, an approach that can characterize many objects similtaniously but also a technology that is incapable of recording the faintest objects of the study.

But the faint galaxies that were missed in the first census represent Geha's highest priority targets. She will bring a sample of these faint objects into her study by using the Triple Spectrograph to obtain spectra of 50 of the lowest surface brightness satellite galaxies.