Marsfield Lecture Theatre

Barbara Catinella

HI properties of massive galaxies -- Barbara Catinella Colloquium

Quantifying how the gas content varies with star formation and structural properties of galaxies is of paramount importance for constraining models of galaxy formation. Equally important is to perform such studies on large and unbiased samples of galaxies, in order to obtain results that are truly representative of the local population. The ongoing GALEX Arecibo SDSS Survey (GASS) is designed to provide such a representative sample for massive galaxies,
with the aim of understanding the role played by gas in the transition between blue, star-forming galaxies and red, passively-evolving systems.

I will discuss how the atomic hydrogen (HI) content of massive systems depends on their structural and star formation properties, and how these scaling relations can be used to identify objects that might be transitioning between blue, star-forming cloud and red sequence.
I will also talk about dynamical scaling relations, and show a relation between baryonic mass and velocity that holds for massive systems, regardless of morphology.
Lastly, I will discuss the relevance of these scaling relations for the future surveys that will be carried out with the Square Kilometer Array and its pathfinders. As an example, I will compare the properties of GASS galaxies with those of a sample of very HI-rich disks at
redshift z~0.2 detected with Arecibo.