What's killing galaxies in extreme regions of the nearby Universe? - Transcript
[On screen: Toby Brown, Plaskett Fellow at the Herzberg Astronomy and Astrophysics Research Centre]
[00:00:05] "How do galaxies evolve" is one of the grandest questions in all of science. Galaxies are defined as vast collections of stars that are born from huge collapsing clouds of cold molecular gas. The physical processes that govern the evolution and the life cycle of these beautiful systems, is closely related to the region of space in which the galaxy resides—known as the galaxy's environment.
[00:00:29] We want to understand the physical connections between galaxies and their environment. Our team has used the world's most advanced ground-based telescope, ALMA (Atacama Large Millimetre/submillimetre Array), in order to complete the largest-ever imaging survey of cold molecular gas of galaxies in one of the nearby universe's most extreme environments—a massive cluster of galaxies known as the Virgo cluster.
[00:00:54] Virgo contains thousands of galaxies whizzing by one another at millions of kilometers per hour through superheated million degree plasma. We already know that when galaxies fall into a galaxy cluster, they can be robbed of their gas. When gas is removed, this shuts down star formation, effectively killing a galaxy and turning into a so-called red and dead object.
[00:01:19] What VERTICO (Virgo Environment Traced in Carbon Monoxide Survey) reveals better than ever before is the physical processes that affect the molecular gas and therefore the star formation cycle of galaxies in the Virgo cluster. VERTICO is surveying the gas in 51 Virgo cluster galaxies, providing some of the most detailed images of gas disks in cluster galaxies ever observed. What these new images are incredibly useful for is revealing how star formation in galaxies, arguably one of the universe's most important physical processes, is affected by the environment in which the galaxy resides.
[00:01:56] What we see with VERTICO is the fingerprints of environment all over the gas disks of these galaxies, so, when the environment is capable of reaching far into galaxies to perturb the cycle of star formation.
[On screen: Official signature, National Research Council of Canada / Conseil national de recherches Canada]
[On screen: Government of Canada wordmark]