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NRAO/Socorro Colloquium Series

Kartik Sheth

NRAO

Constraining the Cosmological Evolution of Disks Using Stellar Bars

Bars are a key signpost in the evolutionary history of a disk galaxy. When a disk is sufficiently massive, dynamically cold and rotationally supported, and sufficient time has elapsed for the baryonic matter to exchange energy and angular momentum with the dark matter halo or the outer disk, the formation of a bar is inevitable. Therefore understanding the evolution of the bar fraction as a function of the host galaxy properties and as a function of redshift provides important clues to the evolutionary history of galaxies. I will present the latest results on local bars from the Spitzer Survey of Stellar Structure in Galaxies (S4G) and discuss the observations for the declining bar fraction with redshift from the COSMOS survey. A plausible reason for the decline in the bar fraction may be that galaxy disks were too dynamically hot to host bars at higher redshift which we have investigated using the DEEP2 / AEGIS data. Together these data are beginning to provide a coherent and consistent picture for the assembly history of disks on the Hubble sequence.



February 22, 2013
11:00 am

Array Operations Center Auditorium

All NRAO employees are invited to attend via video, available in Charlottesville Auditorium, Green Bank Room 137 and Tucson N525.

Local Host: Debra Shepherd

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