Speaker: Ann Martin, Cornell University

Title: ALFALFA and the Hunt for Extreme-Mass Galaxies

Abstract: The ongoing Arecibo Legacy Fast ALFA (ALFALFA) survey is using the Arecibo Observatory to make a census of neutral hydrogen gas in ~ 30,000 nearby galaxies. This method is efficient at finding very low mass, very faint galaxies as well as distant, rare high-mass galaxies. The statistical distributions of gas-rich galaxies in the local Universe will reveal relationships between galaxies’ stellar properties, star formation histories, gas masses, and environment, helping us to untangle galaxy evolution. I will describe ongoing projects that challenge our current understanding of both very small and very large galaxies. I will discuss two statistics, the neutral hydrogen mass function and the correlation function, and how they reflect the cosmological implications of the characteristics of the ALFALFA sample.

As always, the colloquium will be at 12:40 in Room N304, with pizza and soda available at 12:20 for those attending the talk. For details of future colloquia, see the Winter 2011 colloquium schedule.