The Life Cycle of Nearby Galaxies: internal and external processes regulating their gas content

Event Date:
2018-10-15T15:00:00
2018-10-15T16:00:00
Event Location:
Hennings 318
Speaker:
Toby Brown (MxMaster)
Related Upcoming Events:
Intended Audience:
Undergraduate
Event 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.

Add to Calendar 2018-10-15T15:00:00 2018-10-15T16:00:00 The Life Cycle of Nearby Galaxies: internal and external processes regulating their gas content Event 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*&gt;10^9 Msol) and redshift (0.02 &lt; z &lt; 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