Every star in our Milky Way, and in all other galaxies, was born from the collapse of a cloud of hydrogen gas. The importance of cold gas in galaxy evolution is therefore well established, as is its role as a probe of recent environmental effects on galaxies. However, sensitivity limitations mean the extent to which internal and external processes drive variations in the gas-star formation cycle of galaxies remains unclear. In this talk I will show how we take full advantage of the powerful atomic hydrogen spectral stacking technique to overcome this obstacle and provide strong observational evidence of significant and systematic environment-driven gas stripping across the group regime, well before galaxies enter the cluster. This was accomplished using the largest sample of atomic gas and multi-wavelength information then available (28,000 galaxies), selected according to stellar mass (M*>10^9 Msol) and redshift (0.02 < z < 0.05) only. Finally, I will show how state-of-the-art observations of molecular gas in local ultra-luminous infrared galaxies can be used to test if the star-formation process (and the initial distribution of stellar masses) differs fundamentally between galaxies.
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2018-10-15T15:00:002018-10-15T16:00:00The Life Cycle of Nearby Galaxies: internal and external processes regulating their gas contentEvent Information:
Every star in our Milky Way, and in all other galaxies, was born from the collapse of a cloud of hydrogen gas. The importance of cold gas in galaxy evolution is therefore well established, as is its role as a probe of recent environmental effects on galaxies. However, sensitivity limitations mean the extent to which internal and external processes drive variations in the gas-star formation cycle of galaxies remains unclear. In this talk I will show how we take full advantage of the powerful atomic hydrogen spectral stacking technique to overcome this obstacle and provide strong observational evidence of significant and systematic environment-driven gas stripping across the group regime, well before galaxies enter the cluster. This was accomplished using the largest sample of atomic gas and multi-wavelength information then available (28,000 galaxies), selected according to stellar mass (M*>10^9 Msol) and redshift (0.02 < z < 0.05) only. Finally, I will show how state-of-the-art observations of molecular gas in local ultra-luminous infrared galaxies can be used to test if the star-formation process (and the initial distribution of stellar masses) differs fundamentally between galaxies.Event Location:
Hennings 318