Why do galaxies stop forming stars?

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• Asa Bluck
• Wednesday 06 March 2019, 13:15-13:45
• Sackler Lecture Theatre, IoA.

If you have a question about this talk, please contact Catrina Diener.

I will present an overview of my ongoing research into galactic star formation and its cessation in the ‘quenching’ process. From an analysis of the SDSS , we discover that the fraction of quenched central galaxies scales most tightly with estimates of supermassive black hole mass. This result is consistent with models which quench centrals through AGN feedback, particularly in the so called ‘radio-mode’. However, satellite galaxies require additional quenching mechanisms, strongly correlated with environment. I will also present new work examining resolved star formation and quenching in galaxies using the MaNGA survey. Through a detailed machine learning analysis, we conclude that global properties (particularly those most connected with the central regions in galaxies) are the most predictive of quenching in both centrals and satellites. Perhaps surprisingly, the conditions at the spaxel location are largely uncorrelated with quenching. Conversely, we find that local parameters are most effective at predicting the rate of star formation in star forming regions. From these results, we conclude that quenching is a globally governed process (affecting entire galaxies as a whole), but star formation is a locally governed process (varying significantly throughout galaxies, depending on local conditions).

This talk is part of the Institute of Astronomy Seminars series.

This talk is included in these lists:

• Combined External Astrophysics Talks DAMTP
• Cosmology lists
• Cosmology, Astrophysics and General Relativity
• Institute of Astronomy Seminars
• Institute of Astronomy Talk Lists
• Kavli Institute for Cosmology Talk Lists
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• Sackler Lecture Theatre, IoA

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